Chapter 3. Installing GFS

This chapter describes how to install GFS and includes the following sections:


For information about installing and using GFS with Red Hat Cluster Suite, refer to Appendix A Using Red Hat GFS with Red Hat Cluster Suite.

3.1. Prerequisite Tasks

Before installing GFS software, make sure that you have noted the key characteristics of your GFS configuration (refer to Section 1.5 Before Configuring GFS) and have completed the following tasks:

3.1.1. Prerequisite Software

Make sure that you have installed the following software:

  • perl-Net-Telnet module

  • Clock synchronization software

  • Stunnel utility (optional) perl-Net-Telnet Module

The perl-Net-Telnet module is used by several fencing agents and should be installed on all GFS nodes. The perl-Net-Telnet module should be installed before installing GFS; otherwise, GFS will not install.

You can install the perl-Net-Telnet module from the Red Hat GFS ISO. Clock Synchronization Software

Make sure that each GFS node is running clock synchronization software. The system clocks in GFS nodes need to be within a few minutes of each other to prevent unnecessary inode time-stamp updates. If the node clocks are not synchronized, the inode time stamps will be updated unnecessarily, severely impacting cluster performance. Refer to Section 9.9 Configuring atime Updates for additional information.


One example of time synchronization software is the Network Time Protocol (NTP) software. You can find more information about NTP at Stunnel Utility

The Stunnel utility needs to be installed only on nodes that use the HP RILOE PCI card for I/O fencing. (For more information about fencing with the HP RILOE card, refer to HP RILOE Card on page 147.) Verify that the utility is installed on each of those nodes by looking for /usr/sbin/stunnel. The Stunnel utility is available via up2date.

3.1.2. Specifying a Persistent Major Number

The major number is set dynamically when the pool.o module is loaded (either interactively or through an init.d script). In earlier releases of GFS, the major number was set to 121 each time pool.o was loaded. If you want to specify a persistent major number rather than a dynamic major number, edit the /etc/modules.conf file to include the following line, where MajorNumber is the major number that you want to use:

options pool pool_major=MajorNumber

For example, to specify a major number of 121, edit /etc/modules.conf to include the following line:

options pool pool_major=121

You need to edit the /etc/modules.conf on each node running pool.