Snapshots are not backups
Well, frankly, I don’t care. If I told him once, I told him a thousand times, “Don’t go, Julie!” I said, “It’s the Ides of March; beware already. Don’t go, Julie, don’t go …
Rinse the Blood off my Toga - Wayne and Schuster
I grew up on this stuff, and it is actually quite funny.
But bringing this back to a relevant subject.
If I told him once I told him a thousand times, “Snapshots are not backups!”, I said “It’s the Ides of March; beware already. they are not backups, Julie, they are not backups …”
Well if you don’t believe me, then believe VMware. There is official KB 1025279 -
Best practices for virtual machine snapshots in the VMware environment
(modifications are my own, refer to the original for the full article)
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Snapshots are not backups.
As the snapshot file is only a change log of the original virtual disk, do not rely upon it as a direct backup process. The virtual machine is running on the most current snapshot, not the original vmdk disk files.
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The maximum supported amount in a chain is 32. However, VMware recommends that you use only 2-3 snapshots in a chain.
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Use no single snapshot for more than 24-72 hours.
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An excessive number of snapshots in a chain or snapshots large in size may cause
decreased virtual machine and host performance. -
Configure automated vCenter Server alarms to trigger when a virtual machine is running from snapshots. For more information, see Configuring VMware vCenter Server to send alarms when virtual machines are running from snapshots (1018029).
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Confirm that there no snapshots are present (via command line) before a Storage vMotion. If snapshots are present, delete them prior to the Storage vMotion. For more information, see Migrating an ESX 3.x virtual machine with snapshots in powered-off or suspended state to another datastore might cause data loss and make the virtual machine unusable (1020709).
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Confirm that there are no snapshots present (via command line) before increasing the size of any Virtual Machine virtual disk or virtual RDM. If snapshots are present, delete them prior to increasing the size of the disk/s. Increasing the size of a disk with snapshots present can lead to corruption of the snapshots and potential data loss. For more information, see Increasing the Size of a Virtual Disk.
If I told him once I told him a thousand times, “Snapshots are not backups!”, I said “It’s the Ides of March; beware already. they are not backups, Julie, they are not backups… “
And thanks to Raphael Schitz for inspiring this post