Recently, one of our customers asked me if NetBackup for VMware supports the use of a dedicated data store for snapshots. That triggered this blog.
Snapshot is great. Among many of its uses, NetBackup employs it to create a consistent point-in-time image of the virtual machine for the purpose of backup. When a snapshot is active, the writes to VMDK files are directed redo logs. At the end of the backup, the snapshot is released and redo log is played back into VMDK.
The world is less than ideal. What happens if a backup ends prematurely and the snapshot is left behind? Now the redo log grows. What if such situations arise frequently? Now you have multiple redo logs growing in the data store. There are two major issues here.
- The storage space on data store gets used up quickly, if the data store fills up all the VMs using that data store would be affected
- The more snapshots you have for the same virtual...