3.5. Choosing and Configuring devices and Filesystems

Creating devices, logical volumes, and filesystems will have a variety of steps specific to the filesystems and other tools selected. Documenting these is outside the scope of this guide. Please refer to the system and distribution-specific documentation for more assistance in this area.

When you create the volumes and filesystems for use with Linux FailSafe, remember these important points:

• If the shared disks are not in a RAID storage system, mirrored volumes should be used.

• Each device used must be owned by the same node that is the primary node for the highly available applications that use the logical volume. To simplify the management of the nodenames (owners) of volumes on shared disks, follow these recommendations:

  • Work with the volumes on a shared disk from only one node in the cluster.

  • After you create all the volumes on one node, you can selectively shift the ownership to the other node.

• If the volumes you create are used as raw volumes (no filesystem) for storing database data, the database system may require that the device names have specific owners, groups, and modes. If this is the case (see the documentation provided by the database vendor), use the chown and chmod commands (see the chown and chmod reference pages) to set the owner, group, and mode as required.

• No filesystem entries are made in /etc/fstab for filesystems on shared disks; Linux FailSafe software mounts the filesystems on shared disks. However, to simplify system administration, consider adding comments to /etc/fstab that list the filesystems configured for Linux FailSafe. Thus, a system administrator who sees mounted Linux FailSafe filesystems in the output of the df command and looks for the filesystems in the /etc/fstab file will learn that they are filesystems managed by Linux FailSafe.

• Be sure to create the mount point directory for each filesystem on all nodes in the failover domain.