A.3 Backing Up Multihost Data Using Solstice Backup

This section contains suggestions for using Solstice Backup^TM to back up Sun Cluster file systems.

Solstice Backup is designed to run each copy of the server software on a single server. Solstice Backup expects files to be recovered using the same physical server from which they were backed up.

Solstice Backup has considerable data about the physical machines (host names and host IDs) corresponding to the server and clients. Solstice Backup's information about the underlying physical machines on which the logical hosts are configured affects how it stores client indexes.

Do not put the Solstice Backup /nsr database on the multihost disks. Conflicts can arise if two different Solstice Backup servers attempt to access the same /nsr database.

Because of the way Solstice Backup stores client indexes, do not back up a particular client using different Solstice Backup servers on different days. Make sure that a particular logical host is always mastered by the same physical server whenever backups are performed. This will enable future recover operations to succeed.

By default, Sun Cluster systems will not generate the full file system list for your backup configuration. If the save set list consists of the keyword All, then the /etc/vfstab file will be examined to determine which file systems should be saved. Because Sun Cluster vfstab files are kept in /etc/opt/SUNWcluster/conf/hanfs by default, Solstice Backup will not find them unless you explicitly list the Sun Cluster files systems to be saved. When you are testing your backup procedures, verify that all of the Sun Cluster file systems that need to be backed up appear in the Solstice Backup file system list.

Four methods of configuring Solstice Backup are presented here. You might prefer one depending on your particular Sun Cluster configuration. Switchover times could influence your decision. Once you decide on a method, continue using that method so that future recover operations will succeed.

Here is a description of the configuration methods:

• Use a non-cluster node, non-high availability server configured as a Solstice Backup server.

  Configure an additional server apart from the Sun Cluster servers to act as the Solstice Backup server. Configure the logical hosts as clients of the server. For best results, always ensure that the logical hosts are configured on their respective default masters before doing the daily backup. This might require a switchover. Having the logical hosts mastered by alternate servers on different days (possibly as the result of a takeover) could cause Solstice Backup to become confused upon attempting a recover operation, due to the way Solstice Backup stores client indexes.

• Use one Sun Cluster server configured to perform local backups.

  Configure one of the Sun Cluster servers to perform local backups. Always switch the logical hosts to the Solstice Backup server before performing the daily backup. That is, if phys-hahost1 and phys-hahost2 are the Sun Cluster servers, and phys-hahost1 is the Solstice Backup server, always switch the logical hosts to phys-hahost1 before performing backups. When backups are complete, switch back the logical host normally mastered by phys-hahost2.

• Use the Sun Cluster servers configured as Solstice Backup servers.

  Configure each Sun Cluster server to perform local backups of the logical host it masters by default. Always ensure that the logical hosts are configured on their respective default masters before performing the daily backup. This might require a switchover. Having the logical hosts mastered by alternate servers on different days (possibly as the result of a takeover) could cause Solstice Backup to become confused upon attempting a recover operation, due to the way Solstice Backup stores client indexes.

• Use one Sun Cluster server configured as the Solstice Backup server.

  Configure one Sun Cluster server to back up its logical host locally and to back up its sibling's logical host over the network. Always ensure that the logical hosts are configured on their respective default masters before doing the daily backup. This might require a switchover. Having the logical hosts mastered by alternate servers on different days (possibly as the result of a takeover) could cause Solstice Backup to become confused upon attempting a recover operation, due to the way Solstice Backup stores client indexes.

In all four of the above backup options, you can have another server configured to temporarily perform backups in the event the designated Solstice Backup server is down. Note that you will not be able to use the temporary Solstice Backup server to recover files backed up by the normal Solstice Backup server, and that you cannot recover files backed up by the temporary server from the normal backup server.