Port 25: The Open Source Community at Microsoft : Server Center, Management

Technical Analysis: Remote Administration of Windows Systems with SSH

jcannon — Wed, 11 Jun 2008 13:22:00 GMT

Abstract: SSH has largely replaced Telnet for remote administration of UNIX and Linux systems, but has not yet been used much on Windows. SSH is generally considered to be more secure than Telnet and the Berkeley remote commands (rlogin, etc). This paper uses SSHWindows, a minimal package of Cygwin and OpenSSH. It is available from http://sshwindows.sourceforge.net. The paper is written such that an average Windows system administrator can get an SSH server up while understanding how to make use of security features.

Download Remote Administration of Windows Systems with SSH (PDF)

Note: This paper represents testing and documentation in a lab environment. User Account Control (UAC) is an essential security component to Windows and Microsoft does not recommend turning off UAC in production environments.

Managing Towards Open

Sam Ramji — Tue, 29 Apr 2008 19:59:00 GMT

I have the privilege of interacting almost every day with technical and business experts who are creating the future of software—including both core engineering teams at Microsoft and thought leaders across a broad spectrum of open source communities. Especially in the last few months, I’ve been able to take more time to articulate where I think this is going – such as writing how open source has influenced Windows Server 2008 and participating in Infoworld’s roundtable on the state of open source.

I think that many people are seeing that the interrelationship between Microsoft and open source is being changed fundamentally (and for mutual benefit).

Today, Bob Muglia and Brad Anderson announced that System Center will have the ability to deliver automated management across heterogeneous IT environments, such as UNIX and Linux. What I see as a best practice for commercial and community engagement with open source technology plays a big part in this.

Specifically, Microsoft will deliver an agent infrastructure and management packs (MPs) for monitoring Linux and UNIX platforms for System Center Operations Manager 2007. Early partners like Xandros and Quest are delivering cross-platform MPs for MySQL and Apache, and Oracle, respectively. Microsoft and Novell are collaborating on the SUSE Linux Enterprise MP.

The agent infrastructure Microsoft is building to interoperate with UNIX and Linux is built leveraging industry standards and open source such as WS-Management and OpenPegasus. Pegasus is an open-source implementation of the DMTF CIM and WBEM standards coded in C++, designed to be portable, and licensed under an MIT license, and work is underway to integrate with the newly DMTF ratified WS-Management standard. Pegasus already ships as part of major Linux and UNIX distros.

It simply makes great technical and business sense to cooperate with the OpenPegasus community to build upon an industry-standards based, cross-platform technology. Just as important, however, is preserving the virtuous cycle of contribution, benefit, and subsequent contribution: Microsoft is joining the OpenPegasus Steering Committee. The agent technology—being built will be contributed back to the community under the Microsoft Public License (MS-PL), an OSI approved open source license.

I greatly appreciate Allen Brown's positive comments (Allen is the President and CEO for The Open Group) and the support and education we’ve received from the sponsors and maintainers of Pegasus. He said:

“We are pleased to have Microsoft join the OpenPegasus Steering Committee and welcome their commitment as a positive step for the global open source development community. Since The Open Group initiated the OpenPegasus project seven years ago, it has been deployed across a wide range of IT platforms worldwide. We look forward to Microsoft’s active participation in the continuing development of the project.”

Today’s announcement and the business and technical decisions made by the System Center team are a great example of the fact that commercial innovation, industry partnerships, and open source participation can all work together to make the whole greater than the sum of its parts. My enthusiasm and excitement—and my applause for the System Center team, partners like Xandros, Quest, and Novell, and the OpenPegasus community—is tempered solely by my conviction this is not the only or last example of the best of Microsoft, partners, and open source growing together. This is a great day – and there are more great days to come.

How open source has influenced Windows Server 2008

Sam Ramji — Wed, 27 Feb 2008 12:00:00 GMT

When I think about what works really well in open source development and technology, the following things stand out:

Modular architectures
You can find these wherever you see participation at scale – and often a rearchitecture to a more modular system precedes expanded participation. Great examples of this are Firefox, OpenOffice, and X11 – from both the historical rearchitecture and the increased participation that resulted. The Apache HTTP server and APR are good examples that have been modular for as long as I can recall.
Programming language agnostic
A given project uses a consistent language, but there are no rules on what languages are in scope or out of scope. Being open to more languages means opportunity to attract more developers – the diversity of PHP/Perl/Python/Java has been a core driver in the success of a number of projects including Linux.
Feedback-driven development
The “power user” as product manager is a powerful shift in how to build and tune software – and this class of users includes developers who are not committing code back, but instead submitting CRs and defects – resulting in a product that better fits its end users.
Built-for-purpose systems
Most frequently seen in applications of Linux, the ability to build a system that has just what is needed to fulfill its role and nothing else (think of highly customizable distributions like Gentoo or BusyBox, as well as fully custom deployments).
Sysadmins who write code
The ability of a skilled system administrator to write the “last mile” code means that they can make a technology work in their particular environment efficiently and often provide good feedback to developers. This is so fundamental to Unix and Linux environments that most sysadmins are competent programmers.
Standards-based communication
Whether the standard is something from the IETF or W3C, or simply the implementation code itself, where these are used projects are more successful (think of Asterisk and IAX2) and attract a larger ecosystem of software around them.

So where did we apply these ideas to the development of Windows Server 2008?

Modular architectures was applied in multiple areas, but the one that stands out most to me is Internet Information Server 7 (IIS7). IIS7 has been rearchitected for flexibility as 40 individual modules, enable more to be written by community developers or delivered as out-of-band releases. This has already enabled performance improvements and independent evolution, and I expect to see further enhancements.
Programming language agnostic is something we’ve delivered on with support for PHP on IIS7 and the enhancements to FastCGI (which can be used by any of the P* languages). We set a goal of having PHP certified on Windows Server 2008, and we’ve achieved that. We’ll continue to improve runtime, security, and manageability support for non-.NET languages and the applications that are built on them, as well as testing the full stacks of PHP-based applications running on Windows Server, IIS, and SQL Server.
Feedback-driven development based on developer and customer trials (RDPs, TAPs, and Betas in our process) led to a range of “feature completion” developments that connected different components – like connecting Windows Firewall with Active Directory central policy, and the end-to-end improvements in SMB 2.0. Features like the RODC (Read-Only Domain Controller) have become more and more solid through experience with early alpha and beta customer deployments, and requests to enforce things like BitLocker encryption of user disks from a central authority have achieved full support.
Built-for-purpose systems such as DNS, DHCP, file and web serving can be created through wizard-driven configuration thanks to Windows Server Core. The goal of having a minimum attack surface and a small hardware footprint, inspired by the capabilities mentioned above, yet achievable by a broad base of admins has been achieved. Additionally, this has created an opportunity for Windows admins to become much more knowledgeable about the low-level structure of the operating system.
Sysadmins who write code are first-class citizens in the PowerShell-driven infrastructure. We’ve increased Windows administrators’ opportunity to master the full surface area of WMI and demonstrate that mastery in reusable, low-level scripts. As we evolve this to support multiple language bindings and bash aliasing, this should become a comfortable home for highly skilled sysadmins.
Standards-based communication such as in CardSpace (with support for X.509, SAML, Kerberos tokens, and more) and the Web Services stack (not only are all 38 Web Services standard under the Open Specification promise, but our implementations have achieved a high level of interop with Apache’s Axis web services stack), and beta support for emerging standards like Xen virtualization represent a small subset of the standards built into Windows Server 2008.

Overall, we’ve learned and continue to learn from open source development principles. These are making their way into the mindset, development practices, and ultimately into the products we bring to market.

I’ve focused here on “what Microsoft has learned from Open Source” – and ironically, I’ve agreed to do a panel at OSBC on 3/25 with Jim Zemlin of the Linux Foundation on “what Open Source can learn from Microsoft”. As all of the different organizations in IT continue to evolve, we’ll learn from each others’ best practices and make increasingly better software. As in science, this incremental improvement will move all of us forward.

Systems Manageability Part 7 - Log Management and Analysis

kishi — Tue, 07 Aug 2007 15:57:00 GMT

Level-Set – Log Management: This section includes open-source technology directed primarily on host-based logging, log file rotation and log file analysis. Many of these tools are very common free and open-source software tools that are distributed and preconfigured with most of the major Linux systems, including major vendors such as RedHat and Novell.

I. Logrotate

Logrotate is a very popular application utilized in a number of Linux systems, including all RedHat and SUSE based systems. The logrotate utility typically runs periodically via cron, a task scheduling application. The utility will read a configuration file (/etc/logrotate.conf), and archive and compress log files according to the configuration. Administrators can configure when log files should be rotated based on age and size, and how long backlogs should be maintained. Older archived log files can then be swapped out and replaced with newer archives.

II. Syslogd and klogd

Typical Linux systems utilize a syslog daemon to capture log messages from userspace applications and write them to text-based log files or send them to a logging host over the network. The syslogd daemon is often accompanied by a klogd application which is designed to capture and log kernel messages.

The behavior of the syslog daemon can be configured via the /etc/syslog.conf configuration file. All messages captured by syslog are categorized by facility and priority. Messages can then be sent to particular log files or logging hosts, or dropped completely based on their facility and priority attributes.

Facilities

Priorities

- auth or security

- authpriv

- cron

- daemon

- kern

- lpr

- mail

- mark

- news

- syslog

- user

- uucp

- local0 through local7

- debug

- info

- notice

- warning or warn

- err or error

- error

- crit

- alert

- emerg or panic

List of syslog facilities and priorities.

III. Syslog-ng

The syslog-ng application aims to be an enhanced drop-in replacement for the traditional syslog daemon. It provides many of the same features of the standard syslog daemon, but includes additional features such as advanced message filtering based on content, remote logging via UDP or TCP, and the ability to write log files to a database such as MySQL or PostgreSQL. More recent SUSE-based systems such as SLES10 have switched to syslog-ng as the default syslog server.

IV. Viewing Logs

Most log files on a Linux system are stored in plain-text, which means they can be viewed and parsed using a number of different command-line tools. Typical utilities such as tail, head, grep, cat, less, more, sed and awk can be used to view and filter log messages via the command line.

There are also a myriad of utilities designed to parse and view log files via a GUI or web browser. Some utilities are even designed to handle specific log formats, such as those generated by Linux’s Netfilter firewall subsystem.

GNOME System Log Viewer

The GNOME system includes a GTK-based system log viewing application that displays system logs via the GUI.

YaST System Log Module

SUSE-based systems using YaST typically include a module called View System Log (called internally as view_anymsg). Similar to the GNOME System Log viewer, the YaST module allows an administrator to view many of the various system logs without using the command-line.

V. Log Analysis

LogWatch

The logwatch utility is designed to parse system logs and located any entries that might indicate security threat or system failure and send an email report to a designated address. Logwatch is distributed with RedHat Enterprise Linux systems. The following is an excerpt from the RPM description:

“LogWatch is a customizable log analysis system. LogWatch parses through your system's logs for a given period of time and creates a report analyzing areas that you specify, in as much detail as you require. LogWatch is easy to use and claims that it will work right out of the package on almost all systems. Note that LogWatch now analyzes Samba logs.”

LogWatch is typically executed periodically via cron, a task scheduling application.

LogCheck

The logcheck utility is a part of the Sentry Tools project that also includes portsentry, a utility designed to detect port scans. Similar to the LogWatch utility, the software is designed to parse system log files, find log entries that may indicate security problems and send an email to a preconfigured address. Also similar to the LogWatch utility, logcheck relies on the standard cron utility to be periodically executed.

That does it for Log Management and Analysis section. We have one last blog to go and certainly hope that you found the information we have captured for you useful. If you’re running any special toolsets or customizable scripts for log management and analysis and would like to share your experience with us, please send us your feedback and as always, THANK YOU for tuning into Port25.

Systems Manageability Part 6: Patch Management and Online Updates

kishi — Fri, 29 Jun 2007 17:44:00 GMT

Level-Set - Patch Management: Patch Management and Maintenance focuses on those solutions available to deploy and install software update on Linux systems, with a primary focus on Novell based Linux systems. This is going to be a very short blog because the only open source tool that I could find, which is used in a widespread manner, is YaST. I know there are tons of solutions out there, some proprietary like RHN and some custom built. YaST was the only common thread we could recognize. A deeper look at YaST and its online update abilities follows:

YAST Online Update Utility

Probably the most common and important modules in YaST are those related to software management (adding and removing software) and patch management. Software and updates for a typical SUSE system are obtained from software repositories, which can be local or remote software inventories from which new software or updates may be obtained. At a deeper level, the SLES9 package management system utilizes the common rpm utility to install, remove, and update packages and manage the package and dependency database. Although this subsystem is similar to RedHat’s, Novell has chosen a very different approach to distributing its patches, choosing to utilize what are called patch RPMs. With many RPM-based distributions, when a package needs to be updated for one reason or another the distributor will modify or patch the original source tree and recompile/repackage the software to produce a new RPM for that particular package. Therefore in these cases the new RPM will simply be an updated version of the original RPM.

Novell has taken a slightly different approach with patching via RPMs. Instead of updating and repacking the entire package, Novell updates the original source tree, recompiles, and then produces a delta (or a diff) between the original binaries in the package and the newly patched/recompiled binaries. The delta is a binary file that contains information about the differences between two binary files. The deltas will then be packaged within an RPM and distributed to clients. The patch RPM can then be manually or automatically installed in the same way a standard RPM would be installed. An advantage to this technique is that patches are often smaller in size – typically anywhere between 5KB and 8MB depending on the size of the package and the changes being applied. This often allows the update process to progress far faster than it would otherwise when using full RPMs – especially for large applications.

Major updates to the stable SLES9 branch are released as an installable “service pack”. Novell typically recommends installing the service pack files via YaST2, from either a CDROM or network location that contains the service pack files. One may also simply utilize the Online Update module of YaST2 to update the system manually or automatically. In this case, the service pack will be distributed as a large number of individual packages, similar to how RedHat distributes major updates (i.e. RHEL4 U4). Aside from a log file, SLES9 does not currently have an email mechanism to inform the administrator when a patch is automatically downloaded and installed (as RedHat does). However, a log file that contains information about each automatic update is maintained in /var/lib/YaST2/you/youlog. This log is generally very easy for an administrator to read and discover when, or if, a patch RPM was downloaded and installed.

There are other ways to find information about installed patches, however. By default, SLES9 archives each patch RPM that is downloaded and installed. Full RPMs will also be archived if they were installed via YaST2 after the original system installation. This functionality can be disabled with YaST2, of course, although it can sometimes be useful to maintain the archive if a patch ever needs to be reinstalled.

1. YaST Software/Update Repositories

Software repositories are typically added manually via the Installation Source module in YaST or can be scanned using SLP (Service Location Protocol). From this module, one may add references to locations from which to receive updates. These references typically take the form of a URI or a directory path. YaST supports the following software repository references:
FTPHTTP(S)
SMB/CIFS
NFS
CD or DVD
Local Directory
Using this methodology it is also quite common for an administrator to install a centralized repository for software and updates. Updates may then be obtained from Novell by a single server, and other servers on the LAN may then pull patches from the central patch server using one of the above protocols.

2. YaST Security

Although software repositories for SLES and SLED distributions are typically operated by Novell, it is quite possible to add third-party repositories to obtain software not offered by Novell, or even different versions of the same software packages. Novell warns against this, however, since adding repositories not controlled by Novell can result in the installation of untested or possibly malicious software, which ultimately could compromise security, but more likely may result in software instability and RPM package conflicts.
All official software and patches obtained by Novell are cryptographically signed, which can be verified with Novell’s public key. The public keys used to verify these signatures are typically obtained via the official SLES/SLED CDs or DVDs, but may also be obtained via Novell’s website. Once these public keys are accepted and imported, any software package or update obtained with an invalid signature will produce a warning and may not install without user intervention.

3. YaST Automatic Updates

Automatic updates can be configured via YaST’s Online Update Setup module, which allows a user to schedule updates to occur at a particular time either daily or weekly. On the backend, this module simply installs a new cron entry, a task scheduling application, which periodically runs another program to check for and install updates pushed out by Novell.
In earlier SUSE-based systems, YOU (YaST Online Update) had been used to automate the installation of updates packages. The cron utility would execute a shell script called /usr/bin/online_update which would automate the patch installation process. Newer versions of SUSE, including SLED10, utilize a similar process but instead of a shell script a utility called rug is used. The rug utility is the command-line interface to the ZENworks management agent that is present on new SUSE systems.

If you are running any open source based tools or applications in your environment to push patches and manage online update scenarios, we would REALLY like to hear what you have to say. As always THANK YOU for tuning into Port25

Systems Manageability Part Five: Monitoring

kishi — Thu, 21 Jun 2007 14:16:00 GMT

Background: This is Part 5, continuation of the series of 8 blogs I’m doing on Systems Manageability. In this specific blog, I will focus on and explain the third part of the “ontology” which is “Monitoring”

Level-Set – Monitoring: Monitoring and other data collection tools are an essential component of any management strategy. The proper collection and organization of host data allows for manual and sometimes automated reactive corrective measures. This section outlines many of the open source and free software monitoring tools available on the Linux platform. Much of the analysis in this section is focused on the inner workings of these tools as data collection systems, rather than feature comparisons between the various monitoring applications. The WBEM/CIM overview has been placed in this section due to its basis as a data collection and management system, even though its use is not limited the confines of this category.

I.WBEM/CIM: The following section includes an overview of the WBEM initiative and the open-source CIM implementations that exist today. The Distributed Management Task Force (DMTF) classifies WBEM (Web Based Enterprise Management) as the following:

“[WBEM is] a set of management and Internet standard technologies developed to unify the management of distributed computing environments. WBEM provides the ability for the industry to deliver a well-integrated set of standard-based management tools, facilitating the exchange of data across otherwise disparate technologies and platforms.”

Core components and industry standards used in WBEM include CIM, CIM-XML, CIM Query Language, SLP (Service LocationProtocol, for WBEM Discovery) and WBEM URI (Universal Resource Identifier) mapping. The DMTF has also developed a WBEM Management profile template for the purpose of systems manageability. WBEM has been designed to be compatible with all the major existing management protocols, including SNMP, DMI, and CMIP. There are several open source implementations of WBEM including OpenWBEM, WBEM Services, OpenPegasus and SBLIM. These are discussed in more detail below. Additionally, there are both client and server implementations available for the WBEM standard:

WBEM clients include PyWBEM, an open-source WBEM library written in Python, and the Purgos open-source management client for Windows written in C++.
WBEM server implementations include OpenPegasus and OpenWBEM, an open-source client and server written in C++ (Novell has adopted this and added it to SLES9/10).

The following is an explanation of CIM, or Common Information Model, from the DMTF documentation:

“provides a common definition of management information for systems, networks, applications and services, and allows for vendor extensions. CIM’s common definitions enable vendors to exchange semantically rich management information between systems throughout the network. It is a conceptual information model for describing management that is not bound to a particular implementation. This allows for the interchange of management information between management systems and applications. This can be either "agent to manager" or "manager to manager" communications that provides for Distributed System Management.”

CIM includes two components; a specification and a Schema.

CIM Specification: This describes the language, naming, Meta Schema and mapping techniques to other management models such as SNMP MIBs, and DMTF MIFs etc. The Meta Schema is a formal definition of the model. It defines the terms used to express the model and their usage and semantics. The elements of the Meta Schema are Classes, Properties, and Methods. The Meta Schema also supports Indications and Associations as types of Classes and References as types of Properties. Essentially, the CIM specification
CIM Schema: This provides the actual model descriptions. The CIM Schema supplies a set of classes with properties and associations that provide a well-understood conceptual framework within which it is possible to organize the available information about the managed environment. The CIM Schema itself is structured into three distinct layers:

The Core Schema is an information model that captures notions that are applicable to all areas of management.
Common Schemas are information models that capture notions that are common to particular management areas, but independent of a particular technology or implementation. The common areas are systems, devices, networks, applications, metrics, databases, the physical environment, event definition and handling, management of a CIM infrastructure (the Interoperability Model), users and security, policy and trouble ticketing/ knowledge exchange (the Support Model). These models define classes addressing each of the management areas in a vendor-neutral manner.
Extension Schemas represent organizational or vendor-specific extensions of the Common Schema. These schemas can be specific to environments, such as operating systems (for example, UNIX® or Microsoft Windows®). Extension Schema fall into two categories, Technology-Specific areas such UNIX98 or Product-Specific areas that are unique to a particular product such as Windows.

WBEM (CIM) Architecture Diagram

OpenPegasus:

OpenPegasus is an open-source implementation of the DMTF CIM and WBEM standards being driven under the auspices of The Open Group. OpenPegasus is open source and is licensed under the MIT open-source license. The distribution is available via CVS, and as snapshot images in tar, zip, and (self-extracting) exe file formats on the OpenPegasus web site. Based on documentation posted on the site, simply put, Pegasus is an open-source CIM Server for DMTF CIM objects. It is written in C++ and includes the Object manager (CIMOM), a set of defined interfaces, an implementation of the CIM Operations over HTTP operations and their cimxml HTTP encodings, and Interface libraries for both clients and providers. It is maintained to be compliant with the DMTF CIM and WBEM specifications with exceptions noted in the documentation. It is designed to be portable and modular. It is coded in C++ and translates the object concepts of the CIM objects into a programming model. Pegasus is designed to be inherently portable and builds and runs today on most versions of UNIX(R), Linux, and Windows. OpenPegasus includes the following components:

A DMTF compliant CIM Server that processes CIM operations, CIM Indications, and includes class and instance repositories and interfaces for creating CIM Providers and CIM Clients.
Provider interfaces so that providers may be build in multiple languages (i.e. C++, C, Java).
A number of CIM Providers.
A MOF compiler.
A number of CIM Clients to provide usage examples, CIM Server test functions, and administrative functions

OpenWBEM On SLES10:

OpenWBEM is included in SUSE Linux Enterprise Server 9 and 10, allowing any WBEM enabled management console to access configuration information on the system. A CIM schema and a MOF compiler are also included as packages in SLES9 and 10, which can be used to create and import the schema.

## Create the namespace called /root/cimv2

SLES10:/etc/openwbem # owcreatenamespace -n /root/cimv2
Creating namespace (/root/cimv2)
## Import the CIM schema.
SLES10:/etc/openwbem # owmofc /usr/share/mof/cimv2.12/cimv212.mof
[ ... Lots of Output ... ]
Compilation finished. 0 errors occurred.
Compiling and Importing the CIM Schema

## Start the OpenWBEM Daemon.
SLES10:~ # /etc/init.d/owcimomd start
Using common server certificate /etc/ssl/servercerts/servercert.pem
Starting the OpenWBEM CIMOM Daemon done
## Check the status of the OpenWBEM service.
SLES10:~ # /etc/init.d/owcimomd status
Checking for service OpenWBEM CIMOM Daemon running
Starting the OpenWBEM Service on SLES10

II. NAGIOS: Nagios is a system monitoring application designed to monitor remote hosts and applications over a network. The application provides a web-based graphical display that allows one to view the status of nodes and particular applications running on the nodes. The following is an excerpt from the Nagios documentation listing some of Nagios’ feature set: Some of the many features of Nagios include:

Monitoring of network services (SMTP, POP3, HTTP, NNTP, PING, etc.)
Monitoring of host resources (processor load, disk usage, etc.)
Simple plugin design that allows users to easily develop their own service checks
Parallelized service checks
Ability to define network host hierarchy using "parent" hosts, allowing detection of and distinction between hosts that are down and those that are unreachable
Contact notifications when service or host problems occur and get resolved (via email, pager, or user-defined method)
Ability to define event handlers to be run during service or host events for proactive problem resolution
Automatic log file rotation
Support for implementing redundant monitoring hosts
Optional web interface for viewing current network status, notification and problem history, log file, etc.

Nagios can poll servers and obtain data in a number of different ways. The most straight-forward method is to connect to a remote system directly and test to see if the host is available or if a particular service is running. Data internal to the host, such as free memory or processor usage, however, must be gathered using the Nagios agent, SNMP, another custom script or program or a Nagios plug-in called check_by_ssh - which is a standard plug-in designed to run a command on a remote machine and collect the output. The configuration of Nagios is done entirely via text-based configuration files. Hosts and other resources are defined inblocks, which can also inherit information from other pre-defined blocks, making complex configurations possible and more manageable. There are several third-party applications available that provide a web or other GUI interface to assist one with configuring Nagios, but these were not tested for this project. The following configuration block defines a generic host template called “linux-server”. Many of the configuration values such as “24x7” and “workhours” are actually defined in other configuration blocks within the Nagios configuration. This allows administrators to define custom names to a specific time period, such as “workhours”, and use that definition in other parts of the configuration.

define host {

   name                       linux-server
   use                        generic-host
   check_period               24x7
   max_check_attempts         10
   check_command              check-host-alive
   notification_period        workhours
   notification_interval      120
   notification_options       d,u,r
   contact_groups             admins
   register                   0
}
Nagios Host Definition Template

Individual hosts are defined in configuration blocks. Below is a sample configuration for an individual host called management. Notice the use statement is inheriting other definitions from the previously defined generic template mentioned above called “linux-server”.

define host {
   use            linux-server ;Name of host template to use.
   host_name      management
   alias          Management Server
   address        10.197.173.100
}

Finally, hosts may be organized into logical groups for easier management. The following is a hostgroup that defines a group that includes five hosts.

define hostgroup {
   hostgroup_name test
   alias          Test Servers
   members        localhost,management,www,rhel4-production2,network
}

Nagios is distributed with a wide assortment of plug-ins that can be used to obtain data or check a particular service. Plug-ins are distributed as a separate package which must be installed with both the server and the agent if an agent is to be used. The Nagios plug-ins are simply stand-alone executable programs, each of which can perform a particular task and return a result code for each service or subsystem being tested. Since plug-ins are individual scripts or binary programs, they often will accept different arguments to change their behavior and what information they return. The command usage of each plug-in must be defined individually within the configuration files using the define command syntax. Some plug-ins can accept multiple options which can be customized when writing the configuration for a particular system. The define command definition provides a sort of usage template so that Nagios will know how to run the command later. Luckily for new users, the default sample configuration files already provide accurate definitions for the default plug-ins. Once one is familiar with how commands are defined, however, new commands or custom scripts can also be defined here as well.

NRPE: is the Nagios Remote Plugin Executor that is installed on a remote host. It is designed simply to execute Nagios plugins on behalf of the Nagios server and return the results. The same plugins that are installed on the server must then be installed on the remote host for NRPE to utilize. A new plug-in called check_nrpe is also distributed with the NRPE agent and is used to query the NRPE daemon from the Nagios server. NRPE utilizes a rudimentary access control system to assure that only particular Nagios hosts will be allowed to contact the NRPE client. A configuration directive such as the following within NRPE’s configuration file will only allow communication with a particular host:

allows_hosts=10.197.173.100

It is possible to configure NRPE run nearly any command with any arguments, although one is warned against doing this in the documentation. By default, NRPE will only run specific commands and their arguments as specified in its own configuration file (located on the host itself). Meaning that the Nagios server can tell NRPE to execute only specific commands specified in the remote host’s /etc/nrpe.cfg file, but the server may not pass arbitrary commands or plug-in arguments for the agent to execute. Below is a sample NRPE configuration. The specific commands (plug-ins) and arguments must be specified here. The Nagios server can then request NRPE to execute one or more of these commands and return the results:

command[check_users]=/usr/local/nagios/libexec/check_users –w 5 –c 10
command[check_load]=/usr/local/nagios/libexec/check_load –w 15,10,5 –c 30,25,20
command[check_disk_root]=/usr/local/nagios/libexec/check_disk –w 20 –c 10 –p /dev/sda1
command[check_zombie_procs]=/usr/local/nagios/libexec/check_procs –w 5 –c 10 –s Z
command[check_total_procs]=/usr/local/nagios/libexec/check_procs –w 150 –c 200

By default NRPE utilizes SSL communications between itself and the Nagios server. The SSL parameters are generated at compile time and stored in the C header file called dh.h within the NRPE source tree. This header file is then used to compile the NRPE daemon and the check_nrpe plugin. This means that both the NRPE daemon and the check_nrpe plugin must be compiled using the same parameters (typically from the same source tree) if one wishes to utilize SSL communications.

III. Hyperic: Hyperic HQ is a Java-based monitoring application consisting of a central monitoring server and one or more remote agents to report node status information to the server. Hyperic HQ is supported on a wide array of platforms, including Linux, Solaris, Windows, HP-UX, AIX, Mac OS X and FreeBSD. Hyperic distributes two versions of its software;

An open source version licensed under the GNU GPL
and a commercial version called HQ Enterprise which includes additional components and functionality.

HQ Open Source and HQ Enterprise Feature Set Comparison
Note: As of HQ 3.0 thefeature-set distribution between the Open-Source and Enterprise versions has changed. Please see http://www.hyperic.com/products/hq_for_ent.html for more details.

Hyperic Installation and Configuration: Hyperic HQ aims to be quick to install and relatively easy to configure. The installation is performed via the command-line, and will prompt the administrator for all the information (administrator password, database information, etc) it will need to successfully run. Upgrading can also be done relatively easily by simply running the installer with the –upgrade option. Hyperic HQ provides a web interface to deliver monitoring alerts and status information to the end-user. However, unlike other monitoring applications the web-interface is also used as the primary configuration interface for the application. All node and agent details, metric options and alerts may be configured directly over the web interface. The monitoring agent is installed in a similar manner as the server. Because all agent configuration is done via the web interface on the server, the only information the agent installation script needs is login information for the server, the preferred path on the node to which it should install the agent files and various other pieces of information such as the port numbers on which the server and agent will be running. Once the agent successfully registers itself with the server, the administrator can then log in to the web interface and import the new system into its list of monitored hosts. The Hyperic HQ server utilizes the open-source PostgreSQL database application to store configuration and monitoring data. PostgreSQL comes prepackaged with the Hyperic HQ software, and can be installed and configured automatically by the installation system. One may also choose to use an existing PostgreSQL or Oracle database server if one exists. The installation system would then prompt the administrator for information about the database so that Hyperic HQ may log in and store its data. By default, Hyperic HQ stores its authentication information within this database as well, but may also be configured to utilize and external LDAP server if one is available.

Auto-Discovery: A unique feature of the Hyperic HQ monitoring solution is its ability to automatically locate and monitor services and daemons running on the remote node. Once the agent is installed on the remote node it can then scan for a variety of known services and add it to the hosts inventory. Once added to the inventory, metrics and alerts can be configured to monitor that particular service. Hyperic HQ supports two scanning options, auto-scan and file-scan. Agents run an auto-scan periodically by default which scans the process list for known server types. A more comprehensive scan called a file-scan can actually search through the file system on the remote node and locate known applications. Because it requires more time to run and is more resource intensive, this type of scan must be scheduled and configured manually by the administrator.

Alerts and Notifications: Hyperic HQ supports the configuration of alerts based on any metric for any particular resource (such as the host itself) or service running on the host. For example, an alert can be triggered when the Availability metric for a host falls changes at all, or falls below a predefined value. When an alert is triggered an email can be sent to a predefined email address. Depending on the priority of the alert, a message will also be posted to the Dashboard, the Hyperic HQ administration front page. The HQ Open Source version lacks many of the more advanced notification options that are available in the Enterprise version. HQ Enterprise also supports the concept of Recovery Alerts, which are alerts that can be configured to cancel and reset triggered alerts. When an alert is triggered in the Open Source version, the alert will continue to be triggered until the problem is fixed or the alert is disabled. Recovery Alerts allow an administrator to automate the process of disabling an active alert, and then re-enabling the alert when the problem is corrected. HQ Enterprise also supports the option of sending SNMP traps as a notification option.

Hyperic HQ Plugins: Hyperic HQ plugins are distributed as .jar or .xml files that are deployed on the server and the agent. Plugins can be developed to enhance the collection of metrics from certain applications or services, locate and inventory new services and control actions to control specific resources. The Hyperic website provides comprehensive documentation on plugin development. Developing and adding a new plugin tends to be a more complex process compared to Nagios or other monitoring applications. The framework provided by Hyperic HQ, however, provides advanced APIs from which the plugins can query information on multiple platforms. On Windows, for example, Hyperic HQ includes classes which a plugin may use to access Windows specific data and functions. These functions can provide access to performance information, registry data, event log information and the Service Control Manager (SCM). Hyperic HQ also provides support for simple script-based plugins to gather particular metrics. Even individual scripts or Nagios plugins may be imported and configured for use by the Hyperic HQ server and agents.

SIGAR – System Information Gatherer And Reporter: SIGAR is the primary data collection component of the Hyperic HQ agent. The software is designed to collect system and process information from a number of platforms - including Linux, Windows, Solaris, AIX, HP-UX, FreeBSD and Mac OSX. SIGAR is written in C, but Hyperic provides C, C#, Java and Perl APIs which one may use to to integrate SIGAR into their applications. The SIGAR component is licensed under the GNU GPL, and is distributed separately from the Hyperic monitoring agent for potential use in third-party applications. The Sigar API provides a portable interface for gathering system information such as:

System memory, swap, cpu, load average, uptime, logins
Per-process memory, cpu, credential info, state, arguments, environment, open files
File system detection and metrics
Network interface detection, configuration info and metrics
Network route and connection tables

user@linux:~/hyperic-sigar-1.3.0.0> java -jar sigar-bin/lib/sigar.jar
Loaded rc file: /home/user/hyperic-sigar-1.3.0.0/sigar-bin/lib/.sigar_shellrc
sigar> help
Available commands:
        alias          - Create alias command
        cpuinfo        - Display cpu information
        df             - Report filesystem disk space usage
        du             - Display usage for a directory recursively
        free           - Display information about free and used memory
        get            - Get system properties
        help           - Gives help on shell commands
        ifconfig       - Network interface information
        iostat         - Report filesystem disk i/o
        kill           - Send signal to a process
        mps            - Show multi process status
        netinfo        - Display network info
        netstat        - Display network connections
        pargs          - Show process command line arguments
        penv           - Show process environment
        pfile          - Display process file info
        pinfo          - Display all process info
        pmodules       - Display process module info
        ps             - Show process status
        ptql           - Run process table query
        quit           - Terminate the shell
        route          - Kernel IP routing table
        set            - Set system properties
        sleep          - Delay execution for the a number of seconds
        source         - Read a file, executing the contents
        sysinfo        - Display system information
        test           - Run sigar tests
        time           - Time command
        ulimit         - Display system resource limits
        uptime         - Display how long the system has been running
        version        - Display sigar and system version info
        who            - Show who is logged on
sigar>
Example SIGAR usage from the command-line.

And that does it for the “Monitoring” section. There are so many other tools we got a chance to play with like Monit, Argus, OProfile etc. but am running out of space …… As always, please let us know if you found the above mentioned useful and any comments/feedback you may have. Thank you for tuning into Port25.

Systems Manageability Part 4: Systems Configuration

kishi — Fri, 25 May 2007 18:18:00 GMT

Background: This is Part 4, continuation of the series of 8 blogs I’m doing on Systems Manageability. In this specific blog, I will focus on and explain the second part of the “ontology” which is “Systems Configuration”

Level-Set: System Configuration and Management encompasses all tasks related to the configuration of a host in a standardized and (when possible) centralized way. Many projects in this category provide a common configuration interface, either command-line or GUI-based, designed to ease typical administrative tasks. Other projects, specifically Cfengine, provide a higher level policy-based system to provide consistent configuration and state management for a set of systems. Again, in this case there’s lots of different tools out there that can be used but we have focused on the most popular ones such as Webmin, YaST, SSH, VNC and Cfengine. In the paragraphs to follow, we have attempted to lay out our understanding of these tools after using them in the OSSL:

I. WEBMIN: "Webmin is a web-based interface for system administration for Unix. Using any browser that supports tables and forms (and Java for the File Manager module), you can setup user accounts, Apache, DNS, file sharing and so on." Webmin is very modular in design, allowing third-party developers to add support for a particular service or task relatively easily. Many of the tasks involve easing or automating system administration tasks, or editing a configuration file using a specific syntax. Webmin is currently supported by OpenCountry, a company that sells Linux management solutions. The OpenCountry website includes information about Webmin, including two variations of the system that they support.

Webmin Plus: Webmin Plus, is a version of Webmin supported by OpenCountry. According to the website, the Webmin Plus version has been tested by the company and includes new features, specifically support for the back-up and restore application called Bacula (http://www.bacula.org/). Webmin Plus is still freely distributed under a “Mozilla-type” license, and is downloadable via Sourceforge.
Webmin Pro: Last I checked, Webmin Pro had not yet been released, but the following is an excerpt about the product from the OpenCountry website: “...a commercially supported comprehensive product for the entire data center enabling centralized systems administration of mixed distributions, Linux and Windows!”

II. YAST: YaST (Yet another Setup Tool) is an OS installation and configuration utility used primarily in SUSE-based systems. YaST typically serves as the primary control panel interface in, and can be used for a number of configuration tasks – such as adding and removing software, patch management, user management, device configuration and for configuring individual services and daemons. Other common administration tasks such as obtaining system information and reading server logs is also possible via the YaST interface. All of the aforementioned YaST features are implemented as modules, each of which provide a specific functionality or perform certain tasks. These tasks typically involve editing one or more text configuration files on the system in a specific format to configure a specific service or daemon. On other Linux or UNIX-like systems, these tasks are typically performed manually via the command-line.

The YaST utility is very modular in its design, allowing Novell or other third-party providers to add modules into the YaST interface to configure a particular device or service. Many of these modules work independently of each other, and as such are often packaged as individual RPM packages that may be added or removed depending on the software and devices that are installed on a system. YaST modules are written using a scripting language specific to YaST called YCP. Other scripts, such as Perl or shell scripts can also be utilized via a YaST module to perform a particular task. A CIM module for YaST is also distributed with SLES10, which provides a client interface for CIMOM (Common Information Object Manager) to other YaST2 modules. It seems the most common administration task for which YaST is used involves setting up individual package repositories (discussed further in the Patch Management and Maintenance), adding or removing software packages and configuring or initiating online updates. YaST is capable of searching for and locating software on remote repositories, retrieving the software packages, resolving package dependencies, checking the cryptographic signature of the package (if available) and then installing the software on the system. Multiple repositories can be configured. Repositories can be located on a hard disk or CD/DVD, or on a remote system obtainable via HTTP(s), FTP, NFS or CIFS. Once a repository is configured it can then be indexed for later searching. The software search functionality is very powerful, allowing one to search for appropriate software packages using many of the attributes available in the RPM package header – such as the description or contents of the package. Besides software management, the quality and completeness of many YaST modules varies. Many modules (such as the log viewing modules) offer minimal functionality, and only work well enough to provide a few basic configuration options. Complex server configurations will therefore still require one to edit text-based configuration files by hand, or use another configuration engine for the task, such as Webmin. However, many other common tasks, such as configuring display settings or a printer, can be done entirely via YaST.

III. SSH/SCP/SFTP: SSH (Secure SHell) is likely the most widely used remote administration tool for Linux and UNIX-based systems. The typical SSH toolset includes the SSH client and server, as well as the SCP and SFTP client applications for copying files, both of which simply utilize the ssh binary on the backend. The following excerpt is from the OpenSSH project home page: "OpenSSH is a FREE version of the SSH connectivity tools that technical users of the Internet rely on. Users of telnet, rlogin, and ftp may not realize that their password is transmitted across the Internet unencrypted, but it is. OpenSSH encrypts all traffic (including passwords) to effectively eliminate eavesdropping, connection hijacking, and other attacks. Additionally, OpenSSH provides secure tunneling capabilities and several authentication methods, and supports all SSH protocol versions. Since most any task can be performed via the command-line, the OpenSSH utilities are likely the most critical component for a Linux administrator to have available. The remote copy and command execution options allow one to build, deploy and run a script on a number of machines relatively quickly and securely. OpenSSH is typically installed by default in most Linux-based distributions, although in some distributions the server may by default be disabled or blocked by the firewall. "Most common uses of SSH are:

Remote Command Execution: One of the most common uses of the ssh utility is to run commands in remote machines
Authentication: In order to log into, copy files or run commands on a remote host via ssh, one must first authenticate to the remote machine. Local password authentication may be used without any particular configuration on the server. Linux systems that support PAM (Pluggable Authentication Modules) may also use password authentication to authenticate using a number of mechanisms, including NIS, LDAP, Kerberos, or AD (Active Directory).Rather than requiring a user to manually type in a password, a more common authentication option is to use public key authentication. A user’s public key must be inserted into a file on the remote host called authorized_keys before they are allowed to authenticate to that server. This can often be done via the post installation procedures built into kickstart or autoyast.
Tunneling other Applications: Another common application is to use SSH for tunneling other protocols. This is often used to tunnel protocols that are not typically encrypted such as NFS or X11. By using the –Y or –X switches with the ssh client application, one can “turn on” X11 tunneling, allowing graphical applications run on the remote machine to display locally on the administrators workstation. For example, if one were to SSH into a SUSE-based system and run “yast2” via the command line, the YaST display would be tunneled via SSH and displayed on the local system – even though the actual application is running on the remote system.
Cluster Management: When managing a number of Linux servers, such as a HPC cluster, it is typical to have a large number of systems with identical configurations. To ease administration of these systems there have been a number of SSH-based utilities that allow one to run commands on multiple systems, or copy a file to multiple systems, in parallel. The following utilities are all licensed under the GNU GPL.

ClusterSSH: ClusterSSH allows an administrator run to open a remote SSH session to a number of systems at once via a single terminal window, and run commands or alter configuration files on all the systems simultaneously.
PCP: PCP is a tool designed to copy files in parallel to multiple nodes in a cluster or server farm.
GEXEC: GEXEC is a tool that is somewhat complimentary to PCP that provides a parallel remote command execution system for large clusters. The system includes a client and server, as well as a library that allows integration into third-party applications.
PSSH: PSSH is distributed as a suite of utilities that perform many of same functions as ClusterSSH, PCP and GEXEC.
pssh – Parallel SSH, similar to ClusterSSH or GEXEC.
pscp – Parallel SCP, allows one to copy files to multiples nodes in manner a similar to PCP.
prsync – The prsync utility automates running rsync on multiple nodes in parallel, essentially another method of copying files or entire directory trees to a number of remote nodes.
pnuke – The pnuke command can be used to kill a number of processes running on multiple nodes.
pslurp – The pslurp utility is similar to the pscp utility, except that it is designed to copy files from a set of hosts. This allows one to copy, for example, a log file that exists on multiple nodes, to a local directory tree.

IV. Cfengine: “Cfengine, or the configuration engine is an autonomous agent and a middle to high level policy language and agent for building expert systems to administrate and configure large computer networks. Cfengine is designed to be a part of a computer immune system. It is ideal for cluster management and has been adopted for use all over the world in small and huge organizations alike.” Cfengine consists of a userspace application called cfagent and a host of other utilities that reads and parses a series of text configuration files and performs tasks on the host system based on the configuration. The configuration syntax of Cfengine is actually a high-level policy language that allows cfagent to test the system’s configuration and perform corrective actions based on those tests. For example, cfagent may test to assure that a certain line of text exists within a configuration file, and if not it will add the text and restart the associated service. The cfagent utility is typically run on an hourly (or so) basis via cron, a task-scheduling application. This assures that mis-configurations will be found and corrected within a reasonable time frame.

The policy simply tests to make sure an entry for user root exists within the /etc/shadow file, and also checks to make sure the password matches. This assures that all systems have the same password for the root user. The configuration of Cfengine can become very complex, which would likely not surprise those who have had experience with the tool. The structure of the policy language eases this dilemma a bit, as platform definitions can be made and inherited by other blocks to help determine the appropriate action to take. The configuration is essentially a high-level policy language, and thus the various tests must be built and scripted manually. The toolset is, however, enormously powerful when implemented correctly. But as with many open-source technologies, the learning curve can be quite steep, and one must study the complexities of the tool before it can be competently used in a production environment. A version of Cfengine has been ported to the Windows platform to run under Cygwin.

editfiles:
                    # We have different passwords for lab systems and workstations.
       linux.shadowpasswords.md5passwords.(!workstations)::
{ /etc/shadow
    SetLine "root:$1$383J33RL$ XXXXXXXXXXXXXXXXXXXXXX:12984:0:99999:7:::"
    AppendIfNoLineMatching '^root:.*'
    LocateLineMatching '^root:.*'
    ReplaceLineWith “root:$1$383J33RL$ XXXXXXXXXXXXXXXXXXXXXX:12984:0:99999:7:::”
}
       linux.shadowpasswords.md5passwords.workstations::
{ /etc/shadow
    SetLine “root:$1$gcGWA0qS$YYYYYYYYYYYYYYYYYYYYYY:13027:0:99999:7:::”
    AppendIfNoLineMatching ‘^root:.*’
    LocateLineMatching ‘^root:.*’
    ReplaceLineWith “root:$1$gcGWA0qS$YYYYYYYYYYYYYYYYYYYYYY:13027:0:99999:7:::”
}
Example Cfengine policy to check the password for the root user.

The following example Cfengine policy checks for the existence and the contents of the /etc/cron.d/yast2-online-update file for SUSE systems. If necessary it creates the file, and writes a cron entry into the file to schedule a daily check for updates and patches. Upon completion, it then runs the command “/etc/init.d/cron restart” as defined in the suse.restartcrond definition.

editfiles:
        suse::
                { /etc/cron.d/yast2-online-update
                  DefineClasses "restartcrond"
                  Umask 077
                  AutoCreate
                  BeginGroupIfNoLineMatching "^.*[\s\t]+root[\s\t]+online_update"
                      AppendIfNoSuchLine "30 3 * * * root online_update"
                  EndGroup
                }
shellcommands:
        suse.restartcrond::
                "/etc/init.d/cron restart"

Example Cfengine policy to assure that SUSE systems check for updates daily.

And that does it for the “Systems Configuration” section As always, please let us know if you found the above mentioned useful and any comments/feedback you may have. Thank you for tuning into Port25.

Systems Manageability Part 3 - Provisioning and Deployment

kishi — Thu, 03 May 2007 17:29:00 GMT

I want to start this blog with a note of Thanks to Ajay Mungara, the Manageability Developer Community Manager from Intel and “einhverfr”, both of whom gave some very constructive feedback on the previous blog. In the next six blogs to follow, including this one, I will do a “deep-dive” into the six specific areas we covered under the “Systems Manageability” ontology.

Let’s start this blog with the first of the six categories from the ontology - “Deployment and Provisioning”

Level-Set: Deployment and Provisioning as we understand it, encompasses all tasks related to the initial installation of an operating system on remote system, as well as post-installation of software on a remote system. Much of these toolsets are geared toward automated system provisioning and cloning. There’s lots of different tools out there that can be used but we have focused on the most popular ones, namely Kickstart, Autoyast, “Bare-Metal” provisioning and RedHat Network. In the paragraphs to follow, we have attempted to lay out our understanding of these tools after using them in the OSSL:

I.KICKSTART: is an automated installation utility for RedHat-based systems, including Fedora Core and RHEL based systems. Kickstart software requires the creation of a configuration file (similar to an “answer file” in Windows lingo) which contains all the information the installation program will require to install the operating system. The configuration file and all the RPM software packages are typically kept on a remote server such as a HTTP or FTP. The location of the Kickstart configuration file is typically passed to the kernel at boot time. For example, once the bootloader (GRUB, LILO) loads, the user is often presented with a “boot:” prompt that allows the user to pass arguments to the kernel. To load a kickstart configuration file from a remote server one would type the following:

boot: linux ks=http://<server>/location/of/kickstart.cfg

The administrator can then create multiple Kickstart configuration files for different configurations. With the addition of a PXE-based server, much of the provisioning process can be automated. A Kickstart configuration file is simply a text file, which can be created and edited manually with any text-editor. A GUI-based Kickstart file creation program called system-config-kickstart is also available from the Fedora and RHEL distributions. Both kickstart and autoYaST provide the ability to run arbitrary commands during the post-installation phase. This allows administrators to run individual commands, or entire shell scripts to automate any post installation tasks that may be required. RedHat provides a GUI-based tool to assist one in building a kickstart configuration , however in practice it is very easy to customize the configuration file by hand. The ability to run shell commands via the post-configuration phase is simple yet extremely powerful.

II. AutoYaST: is another automated installation utility, similar to RedHat’s Kickstart utility, but used primarily with SUSE-based systems. Novell provides a YaST2 module for autoYaST, which is a GUI tool that can be used to create an autoYaST configuration file – also similar to RedHat’s system-config-kickstart utility. Many of the same rules and procedures used with the kickstart utility also apply to autoYaST. Administrators that need to deploy SUSE clients or servers can create any number of autoYaST configuration files to fit a particular system profile. These can then be used to automate the installation of a SUSE system over a network. When combined with PXE/DHCP setup administrators can deploy and start a SUSE install without using any physical media (i.e. an installation CD/DVD).

III. Bare-Metal Provisioning: Automated deployment tools such as Kickstart and Autoyast support system provisioning via HTTP, (T)FTP and NFS. Completely automated installations can also be configured using the Pre-Execution Environment (PXE), DHCP, tftp and kickstart or autoyast. By automating the boot process, it no longer becomes necessary to manually initialize the installation process via a CDROM or other bootable medium.

Many cluster deployment solutions utilize these very same technologies to deploy large numbers of nodes in a very short time. ROCKS, for example, automates the booting and (re)deployment cluster nodes on the network using PXE, DHCP and kickstart, a process that can sometimes require less than 10-minutes for a single node. Proprietary tools such as CSM, IBM’s cluster management software, also utilizes PXE, DHCP and kickstart or autoYaST to (re)provision cluster nodes as needed.

Configuring a PXE Server for Automated Installations: There are two common utilities one may use to configure a PXE server on Linux. Testing for this scenario was done using a RedHat based system. Therefore some aspects of the following descriptions, such as locations of configuration files, will be RedHat-centric. The general necessity of the configuration and the components, however, are not distribution specific.

pxeos – This utility can be used to configure operating system descriptions within the PXE boot files. Operating system descriptions include the OS name, the protocol used to obtain the OS files (HTTP, FTP, NFS) and the full URI and path to the installation files.
system-config-netboot – The system-config-netboot utility is a graphical application that can perform many of the same tasks as the pxeos utility.

Configuring DHCP: The DHCP daemon can be configured via the /etc/dhcpd.conf file. Those options that are specific to allowing PXE boot clients are listed below.

allow bootp;
class "pxeclients" {
match if substring(option vendor-class-identifier, 0, 9) = "PXEClient";
filename "linux-install/pxelinux.0";
}

Configuring TFTP: The TFTP daemon must first be enabled via xinetd super daemon. The following configuration is added to /etc/xinetd.conf, or sometimes /etc/xinetd.d/tftp, depending on the distribution:

service tftp
{
        disable                 = no
        port                   = 69
        socket_type             = dgram
        protocol                = udp
        wait                    = yes
        user                    = root
        server                  = /usr/sbin/in.tftpd
        server_args             = -s /tftpboot
        per_source              = 11
        cps                     = 100 2
        flags                   = IPv4
}
TFTP Configuration in xinetd.conf
The directory /tftpboot/linux-install is the default used by the system-config-netboot configuration tool. The directory contains kernels and the necessary configuration files required to boot a system and begin a kickstart installation. The configuration file /tftpboot/linux-install/pxelinux.cfg/pxeos.xml contains specific definitions about which network install profiles are available to PXE boot clients.

That’s it for the Provisioning and Deployment section. As always, please let us know if you found the above mentioned useful and any comments/feedback you may have. Thank you for tuning into Port25.

Systems Manageability – Part 2: Scope, Methodology and Ontology

kishi — Fri, 06 Apr 2007 18:14:00 GMT

In my last blog called “Why Manageability Matters” I talked about why we chose to work on “Systems Manageability” as a whole and get a grassroots understanding of it within the context of Linux and Open Source space. In this blog, I’m going to address the Methodology and Ontology of the Systems Manageability project. This will shed immediate light on how we approach, design and implement projects in the OSSL. Let’s start with the main goals and purpose behind the project.

I. Systems Manageability Project Goals:

Survey the scope, depth and breadth of Linux manageability solutions, primarily utilizing open source software
Use the knowledge from the research to develop an understanding of Manageability landscape in the Linux and Open Source
Build and simulate common Linux management solutions in the OSSL (SMORG scale – small and medium sized organizations )
Understand if a cohesive Linux manageability stack exists today--Understand manageability focus from a Linux Sysadmin’s perspective (SMORG scale)

Once we defined what we needed to get into, yet another realization dawned on us, which was the sheer size and volume of the data and information that was staring at us in the face. Let’s just say “overwhelmed” was a mild word compared to what we were looking at. My colleague, Steve Zarkos and I immediately realized that it was time to trim the scope of what we were doing and limit ourselves to what’s achievable in three months and with two people J. This called for drawing up what we considered to be “out-of-scope”, which was:

II. Out-of-scope:

Enterprise-level Management Stacks such as HP Openview, Tivoli etc.
Security and user management, which is a very large area in itself, and would include policies, permissions, authentication, identity management etc.
Asset management frameworks that allow for inventory management, asset tracking etc.
Disaster recovery and planning which would include backup technologies and data protection management

III. Systems Manageability Project Methodology:

The approach taken for the project was simple and scientific. The project was divided into three stages:

Stage 1 – Discovery and Definition: We would explore, uncover and scour the Linux Manageability landscape for toolsets, apps and frameworks prevalent in the SMORG scale workspace today
Stage 2 – Lab Implementation: We would implement the results of our research which would be actual Linux and Open Source products in the Lab
Stage 3 – Analysis and Conclusion: After discovering, defining and implementing Linux and Open Source based manageability toolsets, apps and frameworks in the lab, we would spend time understanding their form, function and experience to draw conclusions

IV. Systems Manageability Project Ontology (classification):

The hardest and most challenging aspect of the project was to develop some sort ontology, characterization or classification of the manageability technologies prevalent in the IT environments today. The diagram below represents the overall "buckets" defined as part of this exercise. Each section of the diagram is broken down to provide a detailed breakdown of each of these Systems Manageability classifications represented:

In the next blog to follow, I will break down the first segment of ontology i.e. “Provisioning and Deployment” and discuss our research with all of you. Meanwhile, we always look forward to hearing from you, our audience and urge you for any feedback you may have about the topic. Thank You for tuning into Port25.

Cheers!

Systems Manageability - Part 1: Why Manageability Matters

kishi — Wed, 21 Mar 2007 20:09:00 GMT

Impetus: This is the 19th year I have spent in the Information Technology business, out of which more than 15 were spent designing and implementing IT environments of various scopes, platforms and sizes. Among several similarities and differences between each implementation, a few constants always emerged, and my favorite of all: Systems Manageability. This question always got asked during every high-profile design review meeting. You know the meeting I’m talking about, the one with the CIO and the IT Director are sitting across the table and asking how we’re planning on managing the environment. The main concern you could see in everyone’s expression was “what sort of manageability needs to be built around for operations and support ?”. So why does manageability matter ? Let’s start with what people imagine, when they think of Systems Manageability. It means different things to people in different roles: the Infrastructure folks imagine uptime and redundancy, the Developers imagine reliability, the Business Managers imagine efficiency. But the answer is so overwhelmingly obvious. Had it not been for systems management toolsets, apps and frameworks, ITPro’s and Admins would be worried sick about everything from uptime to reliability to scalability. So yes, manageability matters, a lot, because it’s the knowledge that “all’s well and running smoothly” that matters to everyone from a CIO to a Developer to a IT Admin.

Importance: Now that we have established the impetus behind why Systems Manageability matters, we should now address the importance tied to it, such as:

Increasingly complex and heterogeneous environments need increased attention: Pick any environment of your choice, whether it’s where you work or the one you hear about the most. It comes with its own share of challenges and oddities. What differentiates one environment from the other is the manner in which it is “run”. The more complex you hardware, software or network stack, the greater is the manageability tied to it. This means that with every component you add to your existing system, you’re only increasing the complexity even further. So is that a bad thing – NO. Because it’s the environment that should be designed with “adaptation” in mind and not the other way round. Thus, having a complex environment simply translates to keeping an eye on more things. Systems Manageability plays a key role in this scenario
Infrastructure sits at the “core” of IT: Here’s an exercise for any of you that may be interested – the next time you see or hear a technology professional being interviewed about a certain “application” or tool that they’ve developed – try to imagine an entire infrastructure that needs to support and run that “tool” or “App”. The exercise will make you think about what’s going on in the mind of an IT Admin who is responsible for running your environment implementation and why Infrastructure is a big deal. Systems Manageability plays a key role in this scenario
End-user productivity has a directly proportional relationship to Performance Tuning and Optimization: Growth comes in spurts and bursts and never an even pace as we all know. This means, various pieces of your hardware, software, toolsets are implemented in various growths and phases. Simply put, growth does not follow a pre-chartered course and timeline. This makes ongoing performance tuning and optimization a necessity. And it has its benefits - it allows you to see the app or toolkit from the eyes of the people who made it. It also gives you the “know how” to make the specific changes in thresholds and values that could mean a difference of night and day, in terms of efficiency. Systems Manageability plays a key role in this scenario
Striking a balance between Manageability and Flexibility is tough: Identity Management and Security issues are now a mainstream topic of discussion and more and more attention is being paid to system security, access and authentication framework. The single reason for putting these in place to ensure that “you are who you say you are”. On the flip side, overly managed and restrictive environments can limit the flexibility of what an end-user can do. That’s why it is always tough to strike a balance between a system that is secure / well managed and one which seems more “seamless”. Systems Manageability plays a key role in this scenario

In the next seven blogs or so to follow, you will get a detailed breakdown on the Systems Manageability project that we have completed in the lab. We will be covering the Project Methodology and Project Ontology in my next blog. As always, send us your comments and feedback and THANK YOU for tuning into Port25.

Infrastructure Management and Strategic Design: Part 4 – Service Management Frameworks

jcannon — Tue, 01 Aug 2006 16:51:00 GMT

Today, the IT departments offering and managing various IT Services might find themselves in what I would call a “pressure-cooker”. They are faced with a multitude of tasks and added pressure to maintain daily operations while driving efficacy, managing the growing complexity of Service Offerings and most importantly, doing so while keeping pace with the industry best practices. This has been one of the most explosive areas of growth and re-examination for the past few years. Back in my Ops days, I trained under ITIL i.e. IT Infrastructure Library and MOF i.e. Microsoft Operations Fundamentals to get a first hand look at some of the best Service Management practices in the industry. No matter how good I thought our Service Management practices might have been, I could not help but to think in terms of the maturity level of the Services that can be achieved by applying these principles. When you get down to it, you realize that the heart and soul of effective Service Management lies in how mature the offering and support model is. I have learnt a lot from the ITIL Service Management Essentials course, which I attribute to research and practices that have gone into developing these models. I’d like to share w/ you what made sense to me:

Bridge Concept: As described in various ITIL formats, Service Management can be referred to as the “bridge layer” between Business and Technology. It is through the conduit of Service Management that core business needs as well as core technologies find their match with each other. This is attained by aligning the Business Needs and Goals of the organization with the various technologies and IT functions that can map to these overall goals
Think Framework: Once you have scoped out, what may be a void in the service hierarchy of your organization, make a commitment to implementing a Service Management and Delivery framework that is suitable for your org. One size DOES NOT fit all and although I am only talking about ITIL concepts here, there are several methodologies you can explore before making the plunge.
Benefits of implementing a Service Management Framework: In just a few minutes after sitting in the ITIL Essentials Training class I was able to get a very crisp idea of what the benefits of implementing a Service Management Framework are. To name a few –

Raising the bar on Service Delivery Quality
More accurate alignment w/ Business Needs
Enhanced relationship between service provider and consumer
Deeper visibility into service complexity
Driving efficiencies with optimal resource utilization

Goals for implementing a Service Management Framework: if and when you do make the commitment to implementing a Service Management Framework, here’s a quick set of goals you can set when you proceed with the implementation of Service Management:

Put an SLA ( Service Level Agreement) or an SLO (Service Level Objective) around the critical and non-critical services you offer, respectively
Manage and monitor the implementation and practice of these SLA’s and SLO’s
Create and publish a service catalog describing the services offered by your IT department/division
Monetize the service management offerings, even if your customers are internal. This will help quantify the service effectiveness and bring measurability across the board

Additional Resources: the itSMF or IT Service Management Forum (www.itsmf.com ) is an independent, non-profit, user group distributed all across the world that has dedicated itself to exploring and promoting IT Service Management concepts and practices.

I am very eager to hear back from those of you that are an integral part of the Service Management Lifecycle. Please share your experiences, challenges and learning with us.

Kindest Regards and have a great week ahead!

Infrastructure Management and Strategic Design: Part 3

jcannon — Tue, 11 Jul 2006 20:17:00 GMT

Part 3 – Adaptation and simulation of Heterogeneous environments under lab conditions

A simple question that has always perplexed me is how software and hardware OEM’s across the world simulate heterogeneous environments under lab conditions. I have witnessed several different approaches, practices and stages of this adaptation and each one of them is unique and correct in its right and merit. I guess, that leaves the “big” question which remains unanswered i.e., how do you bring a “real-life” scenario and manifest it under lab conditions. This is even more challenging because the average test lab for a medium to large organization is no match to the size and complexity of its elder sibling, the Enterprise Data Center, running its production systems, applications and operations. So why squeeze all that complexity into a smaller scale ? Is there one perfect method?– of course not, depends on what heterogeneity means to you/your business. Let’s look at this and why it’s necessary and also share some techniques that may be helpful.

Start with why it’s necessary to represent if not an equivalent amount of heterogeneity within a lab but a comparable one. Start with simple logic – why do we need a lab in the first place ? In most cases it’s an environment we can turn to and run processes, tests and simulations which we dare not try in a Production Environment. However, the caveat here is that if we do want to test a tool or an app that we’re about to roll into a production environment, our best bet is to test it in the lab with conditions mirroring as closely to the production environment as possible. It’s also a place where we can develop workarounds, fixes, documentation, implementation practices and as much supplementary support mechanism as we’d like before we bite the bullet and push the tool or app into production. The expectation we keep in mind when we do that is that results from the lab and production rollout should bear a resemblance like that of the “Partridge Family” and hopefully not of the “Manson Family”. Okay, bad joke but you get the point.

Now on to “Tips and Tricks” to help with the process of adaptation and simulation of a lab environment that mimics your production one. Here’s what I found useful:

Deployment Methods: Using similar deployments tools, techniques and methods in the lab that are already in use in the production environments makes one aware of “delivery mechanisms” and the path, process the deployment cycle will take when released
Configuration Management: Extreme familiarity and knowledge of the configuration options of not just the delivery mechanism/s but also of the tool/s or app/s is something as valuable as having that Swiss knife in your pocket – you just never know when you’re going to need it
What Business Scale ?: Never hesitate to walk out of the lab and have a conversation with decision makers who chose the tool/app. Find out more about what their expectations out of this application are (by now I know some of you may be cringing in your chairs but I am dead-serious on this one). This is the best way to learn if the application should be tuned towards business scales such as Reliability, TCO, Scalability, Performance, High availability or whatever
Manageability: My personal favorite – always have a lifeboat handy i.e. when the fit hits the shan, will you still be able to recover the system, do a roll-back, connect remotely and most importantly, keep the service/s up and available
Driving Efficiencies: Most IT departments have to squeeze every efficiency they can out of their budgets, and labs are a luxury when they have to deliver results to CTOs. So what’s the best way to accomplish testing, or simulation, on a budget. How does someone with no extra money support such an effort. There’s some creative resource utilization that can be implemented such as:

Rotation of production hardware coming up for decommissioning and reallocating such resources to the lab
Making use of evaluation copies and licensing i.e. since most lab testing scenarios only extend to short periods to drive testing
Using down-time to allocate personnel to testing efforts i.e. if there’s lag time between two projects, using that time and headcount effectively to drive testing

And finally a small anecdote to help put things in perspective. In my past life, I remember several years ago when I was still on the east coast, I worked on implementing an asset tracking tool for desktops spread through the environment. We tested the tool on individual desktops and did not care about running the entire scenario using network connectivity across the simulation. We were told by the vendor that the tool uses less than 1% of CPU as negligible amount of memory. After random tests, we rolled out the tool and the purpose of the tool was to run a script and send the results back across the network. However, due to ACL’s in place, which we forgot to account for, and lack of validation of packet delivery, the desktops stopped responding. This was an expensive lesson in why we should test the waters to the best possible extent before setting sail.

Just a few thoughts and hope it triggers some more for everyone out there. As always, please do let me know if that has been useful and/or if you have a specific topic in mind you’d like us to write about.

-Kishi

Managing the Lab: SMS and our mixed environment

admin — Fri, 31 Mar 2006 15:00:00 GMT

Getting the Open Source Software Lab up and running presented a number of challenges – not the least of which was how we were going to manage fifty Linux distributions, fifteen versions of UNIX, and multiple Windows instances deployed across literally hundreds of physical and virtual servers. This is quite a job for any management solution. Being the pragmatists we are, we decided to use this to test the viability of SMS (Microsoft Systems Management Server) using VMX (Vintela Management Extensions) in a mixed environment.

We deployed the solution and found it to be capable of handling our environment. Currently a large part of the lab is managed by SMS and VMX. When we describe this to people we are often asked, "Why does Microsoft supports this kind of solution? Why do we care about mixed environments?"

We asked Bill Anderson, Lead Program Manager on the Windows Management Team, and here is what he had to say:

Bill Anderson
Not really, but his lab is less camera-shy.

The first question I always get asked is, “what really was the catalyst for SMS to seek out a partner to provide extensions to OSS/Linux? Simple – our customers demanded it. Our existing SMS customers are managing both desktops and servers, and have a multitude of platforms in production in those environments and wanted to extend the success they have with SMS on Windows to those additional platforms. And, as we’re driving SMS into new customers, it has become one of the top requirements for customers – an integrated solution to manage all their critical platforms.

Now, the second driver was the WAY in which the market was doing cross-platform management. It’s, well, “suboptimal”. You either take 2 management systems (Windows mgmt, non-Windows mgmt) with their own array of servers, agents, and databases – and join the databases, or you try to take one agent that runs on all platforms, and you can then only join the things that are the same/similar. You either get a bunch of extra infrastructure with no leverage of skillsets, or you get a lowest common denominator management experience.

What we did was option 3 – build a single shared infrastructure that was extensible at the protocol, data, and UI layer, and then take the 2 leaders in the field to build from that same plumbing. So, we optimized our agents for the work on Windows, and we worked with the Vintela team as the experts in managing OSS/Linux to really optimize their experience for that platform. So, what does a customer get? 1 database, one UI, one protocol, and agents unique to each platform. Low operational cost, leveraged skillsets, and the opportunity for each vendor to really highlight the best they could do on each platform. Some of the things that Vintela can surface and manage on the Linux platform, using SMS as a pipeline, are pretty amazing! They’ve extended our UI to really expose all the remote functions available on Linux from the different vendors like Red Hat, SuSE, HP, and Sun. My challenge to them was to make Linux look BETTER in SMS than Windows does. We’ll try to make Windows more manageable by adding more, not by restricting. And the results are pretty compelling. As Andi put it in Network World's Network/Systems Management Newsletter: “Yes, you read that correctly - Microsoft tools can make Linux management easier. To its credit, Microsoft has made this easier through partnerships and programs like its Dynamic Systems Initiative - a commitment from Microsoft and its partners to deliver self-managing dynamic systems…(snip). This allows enterprises to leverage their investment in native Windows tools to make them a very effective management platform for diverse networks. “

How the Vintela solution works is really pretty simple. They take a WBEM based agent (they are the project maintainer for OpenWBEM) that runs on the major OSS platforms, that points at a URL that is our Management Point role. They extend our MMC based UI and voila – instant management for Linux! No database schema changes required, no separate middle infrastructure, etc. Initially, there was an ISAPI.dll “gateway” they had built to convert their agent protocol to ours at the Management Point, but we’ve worked to even eliminate that as they are now using our native protocols. As you can see, this is a slam dunk for a customer using SMS already to manage Windows that wants to extend it to manage Linux. It’s amazing to walk to an SMS admin, open their admin UI, have them see machine collections based on Linux versions/vendors, and be able to send software to a group of Linux machines in about 3-4 clicks. But, we’re even seeing customers use THIS as a solution for managing Linux only! Vintela has done a great job of really just using the SMS UI, database, and pipes as their engine, and leveraging all the

manageability on the native Linux platform to provide a great stand-alone tool for managing Linux. Inventory, software distribution, patch management and remote tools – all in one single UI and infrastructure. The other key is really leveraging the OpenWBEM work to provide consistent management on different Linux versions. The Vintela team has done a great job of driving consistency via OpenWBEM, but still leverage all the extra tools and functions provided by each Linux vendor. If I were managing Linux systems (not a lot of that around here by the way!) I’d definitely use it!

For more info, I’d also suggest taking a peek at the EMA document they did for Vintela at http://www.vintela.com/products/vmx/docs/Managing_Heterogeneous_IT_with_SMS_EMA.pdf.