Installing OCFS Software Oracle Database Tips by Donald Burleson

The instructions for downloading and burning to disk all of the elements required to install OCFS can be found in Chapter 4. Review Chapter 4 and copy the files into the /tmp directory.

OCFS software must be installed as root using the rpm -ivh command. Do not login as another user and use the sucommand to install and configure OCFS! Make sure you login directly as root. There are four elements that need to be installed. Some of the files installed are dependent upon others, so install them in the order shown in Figure 5.6, and install the software on all nodes.

OCFS requires a version of modutils that is older than the one already installed with the Fedora kernel, so it must be forced in with the --force switch as shown in Figure 5.6. The necessary version of modutils is included in the code depot.

Configuring OCFS

Once installed, OCFS can be configured by the root user. Launch the OCFS Tool with the command ocfstool. Click tasks, and then select generate config. As long as the network has been set up properly, the default values will be correct. This will create the text file /etc/ocfs.conf. Generate a configuration file and then quit the OCFS tool program. Viewing the configuration file is easy to do with the more command as seen in Figure 5.8. Finish this step on each node.

The parameter comm_voting= 1 tells OCFS to prefer the network to share voting information among the nodes. With this configuration if the network becomes unavailable, it will fail over to sharing voting information via the disk. If comm_voting = 0, voting information will be shared via the disk only. Using the network is preferred because it is faster and offers a fail-over option.

With the config file generated on each node, run the command load_ocfson each node as shown in Figure 5.9. 

The module will load with warnings. This is expected on Fedora Core 1. The load_ocfscommand does not need to be run after rebooting because OCFS will be loaded automatically from the script /etc/init.d/ocfs, which was written to disk and turned on with chkconfig when OCFS was installed.

Create the directories to be used as mount points. Use the mkdir command and the chowncommand as shown in Figure 5.10 to create and change ownership of the directories on each node.

The directories /u02 and /u03 will be used to mount the shared partitions on the external drive.

With OCFS configured and loaded on each node in the cluster, ocfstool can now be used to format a partition on the shared fire-wire disk. Formatting a partition needs to be done from only one node. To do this, launch the OCFS tool again with the command ocfstool. Using the OCFS toolbar, choose Preferences and switch to Advanced as shown in Figure 5.11. This will add a few more options such as the force command.

From the toolbar, choose Tasks and then Format. A new window will appear as shown in Figure 5.12.

Use the settings shown in Figure 5.12 for the partition /dev/sda5, and use the mount-point /u03 for the partition /dev/sda6. The force option is useful when overwriting a pre-existing OCFS partition.

If you want to learn RAC at home, get the bestselling book "Personal Oracle Real Application Clusters" by Edward Stoever. You can buy it direct from the publisher for 30%-off and get instant access to the code depot of Oracle tuning scripts.