Backing Up and Recovering Voting Disks

Backing Up and Recovering Voting Disks
What is a voting disk and why its needed ?The voting disk records node membership information. A node must beable to access more than half of the voting disks at any time.
For example, if we have seven voting disks configured, then a node mustbe able to access at least four of the voting disks at any time. If anode cannot access the minimum required number of voting disks it is evicted(NODE EVICTION), or removed, from the cluster.
Backing Up Voting Disks
When to backup voting disk ?
1)After installation

2)After adding nodes to or deleting nodes from the cluster

3)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 we want to back up the voting disk contents:-
dd if=voting_disk_name of=backup_file_name
If our 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 we 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; we 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 or crash, and no longer usable by Oracle Clusterware, we can recover the voting disk if we have a backup file.
dd if=backup_file_name of=voting_disk_name