How much space needed for snapshot

[neilpotter]

We have a SAN with 4 x Datastores. One of these data stores hold 3 x 2TB VMDK's that have been joined in windows to form a single 6TB Data volume.
If i wanted to back this up with Veeam, will I need an additional 6TB space on the datastore to create the snapshots, or does it not work that way?

Thanks

[veremin]

It depends of type of VMs you have in your environment. More specifically, the amount of changes they produce regularly. According to the best practices, it’s strongly recommended to have 10% free of datastore in case of general VM, and, at least, 20% in case of VM with high change rate (SQL, Exchange, etc).

Thanks.

[neilpotter]

Thanks.

So as a check, if I increase to say 10% space as it's only a file server, is there any danger if the snapshot were to fill the datastore, or would I be right in thinking it would throw up an error that it couldn't create the snapshot, then remove it?

[veremin]

The job would throw an error, the snapshot would be merged.

[Vitaliy S.]

Also If you want to monitor VM snapshots and get notifications about orphaned snapshots, you can use Veeam ONE (part of Availability Suite).