In any clustered environment, you need Web-enabled access for monitoring and managing the resources. Web access makes management easier by letting you manage and monitor the resources using a Web browser with proper user access. Webmin is an open-source tool that incorporates many modules for basic system administration. Webmin provides the basic framework -- you can easily add other modules to the tool to support other function.
This brief set of instructions complements the previous article IBM Cluster Systems Management: An installation guide. Webmin is a browser-based tool for UNIX system administrators. IBM Cluster Systems Management (CSM) provides modules to integrate with Webmin to monitor a cluster. The CSM Webmin modules -- part of a package called xCSM -- were introduced shortly after the earlier article was published. The xCSM Web interface is a browser-based graphical interface for CSM, available for both AIX® and Linux®. See Resources to view some xCSM screen shots on the IBM xCSM Utilities software Web page.
Webmin provides many system management capabilities, including networking, backup, user management, RAID implementation, and disk management. According to the Webmin Web site (see Resources): "Using any browser that supports tables and forms (and Java™ for the File Manager module), you can set up user accounts, Apache, DNS, file sharing, and so on. Webmin consists of a simple Web server and a number of CGI programs that directly update system files, such as /etc/inetd.conf and /etc/passwd. The Web server and all CGI programs are written in Perl version 5, and they use only standard Perl modules."
You can download Webmin from the Webmin Web site (see Resources), which also contains information and ideas about how to use the tool.
(Note: All the figures listed in this article are only partial images and do not show full screen shots.)
The following hardware and software were used to perform the tasks described in this article:
- IBM System x346 (model number 8840-11A)
- Red Hat Enterprise Linux (RHEL) version 4.0, update 4
- IBM Cluster Systems Management Version 1.6 (Version 1.6.0.1)
- Webmin modules
xcsm.web-1.3-16.noarch.rpmandxcsm-1.4-13.noarch.rpm. Download these modules from the IBM xCSM Utilities software area of the CSM download Web site (see Resources).
- The Webmin tool itself,
webmin-1.300-1.noarch.rpm. Download the latest rpm from the Webmin Web site (see Resources).
-
autoupdate-5.3.12-1, or higher, andexpect-5.42.1-1, or higher. These software modules should be available to install along with Webmin. You can download the latestautoupdaterpm from the CSM download Web site (see Resources). Theexpectmodule is part of the Red Hat distribution.
Figure 1. Viewing the setup diagram
Follow these steps:
- Install RHEL4 U4 on all the computers in the environment, such as
master.my.com, node1.my.com, node2.my.com, andnode3.my.comas shown in Figure 1.
- Install IBM CSM v1.6 on
master.my.comas explained in IBM Cluster Systems Management: An installation guide..
- Install
webmin-1.300-1.noarch.rpmonmaster.my.comas shown in Listing 1.
Listing 1. Webmin rpm installation#rpm -ivh webmin-1.300-1.noarch.rpm
Now, you can access the Webmin interface from your browser at the locationhttps://master.my.com:10000.
- Install
xcsm.web-1.3-16.noarch.rpmandxcsm-1.4-13.noarch.rpmonmaster.my.comas shown in Listing 2.
Listing 2. xcsm.web and xcsm.rpm installation#rpm -ivh xcsm.web-1.3-16.noarch.rpm #rpm -ivh xcsm-1.4-13.noarch.rpm
- Use your browser to access the Webmin interface at the location
https://master.my.com:10000. Specify username and password as set on themaster.my.comcomputer. On successful login, the Web page shown in Figure 2 opens.
Figure 2. Viewing the Webmin interface
- Click the Cluster tab, and then click Cluster Systems Management. The Web page shown in Figure 3 opens.
Figure 3. Viewing the Cluster Systems Management page
On this page, you see all the activities to perform on the cluster nodes in the Node Actions section.
- If you defined
node1.my.comand registeredmaster.my.com, you see the nodes in the Cluster Systems Management page as shown in Figure 4. Note: For this example,master.my.comis also added as a cluster node.
Figure 4. Registering and defining nodes
- Now, test as follows:
- To modify the attributes of
master.my.com, select that node and click the Attributes button. After changing the HW Type and saving the change, you see the output shown in Figure 5.
Figure 5. Modifying attributes of master.my.com
- To monitor the performance of
master.my.com, select that node and click the Perf Mon button. The output appears as shown in Figure 6.
Figure 6. Monitoring the node performance
- To copy files from the CSM server to the selected nodes, select
node1.my.comand click the Copy button. This opens the panel shown in Figure 7.
Figure 7. Copying files to node1.my.com
- You can also register a new condition or response using the task manager on the left side of the Webmin interface. You can even start or stop the registered conditions through the same panel, as shown in Figure 8.
Figure 8. Monitoring conditions
Webmin is a good tool to use because it offers a standard Web interface for UNIX cluster system administration. You need not use secure shell (ssh) or telnet to communicate with the cluster master to perform any activity on your cluster; you can perform these activities with the Webmin interface instead. This article described how to install Webmin, and it described the required modules that help you to access your CSM server from anywhere in your network. After you install and test Webmin to ensure it is working properly, your cluster management work will be much easier using the Webmin simple Web interface.
Learn
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IBM xCSM Utilities software: Check out screen shots from the IBM xCSM modules.
-
CSM documentation: Get the latest information about Cluster Systems Management.
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CSM for Linux V1.4.0.10 Planning and Installation Guide: Get planning and installation information for setting up a CSM cluster for Linux.
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Backing up and restoring CSM and ERRM data: Learn how to back up and restore CSM and ERRM data.
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Webmin Web site: Download the Webmin rpm and get more information about Webmin.
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Harish has been with IBM since 1998 during which he spent five years at the India Research Lab, one year at the IBM T.J.Watson Research Center, and two years at the Linux Center of Compentence. Harish currently leads the Linux Center of Competence in Bangalore, India. You can contact him at hchauhan@in.ibm.com.
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