SAN Snapshots on a Regular Backup Task

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A virtual machine (VM) snapshot is a point-in-time copy of the VM, which allows rolling back to a previous known state of the VM. It is helpful when restoring data during disaster recovery or backing up different states of the VM and its data for analytics and testing.

The longer the hypervisor is required to keep a VM Snapshot active, the greater is its negative impact on the VM’s performance. The slowness results from the extra system overhead incurred when maintaining a point-in-time image for the backup duration - an I/O intensive process that could take several minutes or hours. Such consequences discourage organizations from taking more frequent snapshots, making them more vulnerable.

On the other hand, a storage snapshot can rapidly capture the point-in-time state of the VM from a momentary VM snapshot that only lasts seconds and allows normal application behavior to resume quickly. Further, backups can be taken directly from the SAN where the storage snapshot resides without disturbing the application VM. More frequent snapshots are possible with fewer gaps between known good recovery points. Storage systems offering plug-ins based on the Veeam Universal Storage API minimize the impact of VM snapshots by using storage snapshots for backups.