Question

Running VMS, Backup and Replication simultaneously, will it work , considering the snapshot clash for same vms


Userlevel 3

Backup frequency - Daily one  incremental and Weekly active Full

Replication - Every 15 Minutes


10 comments

Userlevel 7
Badge +20

If you have both then at the time the backup runs it might conflict with replication. I have never tested this myself but since replication uses snapshots too one would assume a conflict.

Userlevel 7
Badge +6

From experience you do get a pause while the backup runs. You could modify the schedule window for the replicas to exclude them from running while the backup completes or just let it queue and complete naturally.

The one issue is how big a delta you will have from the backup running and completing and replica resuming and your 15 minute RPO for the replica.

Userlevel 7
Badge +6

I’ve wondered this as well…but I’ve never tested.  My assumption was always that the backup would probably be delayed until the previous replication completed, slip in there and run, and then resume the replications.  Makes me wonder if CDP replication would be a better option if you’re trying to replicate every 15 minutes and if this would be less disruptive to the backup cycles.

Userlevel 7
Badge +17

CDP does not use snapshots, therefore it does not compete about snapshots with the backups.

I think, CDP should be less disruptive to backups and should be running during backups.

I have no practical evidence for this, though, because we don’t use CDP...

Userlevel 7
Badge +14

In my opinion, one job would block the other from processing. So either the backup or the replication job can process a VM, but not both at the same time. They also have the same priority, but you could configure the backup job for high priority. Or exclude your backup windows from the replication schedule.

 

Userlevel 7
Badge +6

CDP does not use snapshots, therefore it does not compete about snapshots with the backups.

I think, CDP should be less disruptive to backups and should be running during backups.

I have no practical evidence for this, though, because we don’t use CDP...

 

Exactly what I was thinking.  I haven’t had any issues with backups on my VM’s using CDP.  I have three VM’s using CDP with a 15 second RPO.  Working great so far aside from trying to keep up with such a low RPO.  Still tweaking things there.

Userlevel 7
Badge +6

In my opinion, one job would block the other from processing. So either the backup or the replication job can process a VM, but not both at the same time. They also have the same priority, but you could configure the backup job for high priority. Or exclude your backup windows from the replication schedule.

 

 

I was just wondering about setting the backup as a high priority.  I’ve never had to use the Priority checkbox though.  Or, like you said, create a window in replication so that backups can run.

Userlevel 3

Thank you all for reply, i will try CDP and Backup option .

Userlevel 7
Badge +11

@SantoshP : try to avoid running the replication jobs and backups jobs at the same time. Make sure you have a backup window and a replication window. I suggest running first the replication jobs because those are always incremental (except the first time 😂) so regarding of the block-changes they are more or less always have the same duration. Running the backup jobs depends on incremental, synthetic full or active full. Therefore running those after the replication window eliminates running them at the same time.

Userlevel 7
Badge +3

Never a good idea to run multiple backup products on a device. If you must, make sure to schedule them far apart to make sure the VSS writers have enough time to free up for the other product to run.

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