Replication - does it snapshots on every replication?

[yps]

Hi!

Does Veeam do a snapshot and queices before doing replication? Or how does it works? What performance inpact does it have?

[foggy]

Yes, snapshot is created on each job run. I recommend to review this topic and the corresponding user guide section (p.44) for basic understanding.

[yps]

Thanks.
So if running VMs with hugh changes (like SQL), it will probably impact production (because of stun/unstun) if running with short interval.

[foggy]

Exactly. We have a huge existing topic regarding that, probably worth reviewing.

[Gostev]

Actually, the linked thread is completely NOT applicable here, as those issue only arise when snapshots stays opens for a long time (and grows very large) - such as with full or daily incremental backups.

Since OP is talking short replication intervals, those will be completing under 1 minute or less, so there will be no problems due to the snapshot commit.

@Magnus where impact may come from is from VSS freeze/unfreeze, but in case with SQL (which is designed to handle crashes) you could as well just disable application-aware processing for your replication job for crash-consistent replicas, this way the impact on production will be absolutely minimal.