Backing Up and Recovering Voting Disks
What is a voting disk & why its needed ?
The voting disk records node membership information. A node must be
able to access more than half of the voting disks at any time.
For example, if you have seven voting disks configured, then a node must
be able to access at least four of the voting disks at any time. If a
node cannot access the minimum required number of voting disks it is evicted, or removed, from the cluster.
Backing Up Voting Disks
When to backup voting disk ?
- After installation
- After adding nodes to or deleting nodes from the cluster
- After performing voting disk add or delete operations
To make a backup copy of the voting disk, use the Linux dd command. Perform this operation on every voting disk as needed where voting_disk_name is the name of the active voting disk and backup_file_name is the name of the file to which you want to back up the voting disk contents:
dd if=voting_disk_name of=backup_file_name
If your voting disk is stored on a raw device, use the device name in place of voting_disk_name. For example:
dd if=/dev/sdd1 of=/tmp/voting.dmp
Note : When you use the dd command for making backups of the voting disk, the backup can be performed while the Cluster Ready Services (CRS) process is active; you do not need to stop the crsd.bin process before taking a backup of the voting disk.
Recovering Voting Disks
If a voting disk is damaged, and no longer usable by Oracle Clusterware, you can recover the voting disk if you have a backup file.
dd if=backup_file_name of=voting_disk_name
