Replica from backup source - multiple repositories

[glennsantacruz]

Question: when configuring a replication job and selecting "Source" -> "From backup files (latest VM state available in backups)", and selecting *multiple* repositories, is there a "tie-breaker" rule applied? For example, we have backup copy jobs defined to copy backups from "site A" to "site B" ( typical DR ), and we have defined replica jobs to replicate from "site A" to "site B", with "site B" selected as the source repository ( assuming, of course, that the backup copy jobs will properly copy restore points into "site B" for consumption by the replica job ). In some circumstances, the backup copy job may take longer than anticipated, and the replica job may start prior to the backup copy completing. In this circumstance, the replica job will not detect the latest restore point available, since the job is configured to search only "site B" for restore points.

Now suppose we modify the replica job to search both "site A" and "site B" for restore points. If the backup copy job from "site A" to "site B" completes prior to the replica job start, then the replica job should detect the same restore point in both "site A" and "site B", leading to a potential tie-breaker decision on which repository to use as a source. The VBR GUI provides no means of ranking repositories for selection, leading me to ask the question: how are tie-breaker scenarios treated? In our case, we would absolutely prefer that the replica job prefer "site B" for the source, since that site is the target location of the replica itself and would not incur major overhead in transferring over a WAN connection. If "site A" were selected as source, that would mean the restore point data would need to travel from "site A" to "site B", but that transfer would have already taken place earlier via the backup copy job.

Is this scenario covered already by some internal logic within Veeam, or should we address this by tweaking/adjusting backup copy job intervals and replication job start times ( seems like a potential hit-and-miss to get the timing just right ).

[foggy]

Hi Glenn, the Veeam B&R logic is to always take the latest possible restore point (by creation time).

[glennsantacruz]

Thanks for the response. I had the impression that a backup copy job would copy restore points exactly as they exist. Does this mean that the restore point has a 'creation time' attribute as well as an actual 'restore point date/time' attribute, such that backup copy jobs may result in the same restore point, but with a more recent creation time?

[foggy]

Yes. Backup copy does copy restore points exactly as they exist, however, the files on the target storage have a newer creation date/time stamp, which is taken into account by the replica jobs.

[glennsantacruz]

Thank you for the clarification. Based on your response and updated understanding of the restore points, I believe it would be safe to configure the replication jobs to use both repositories ( "siteA" and "siteB" ), and trust that the replicas would use the most recently-created restore point regardless of repository. If the backup copy job completes prior to the replica job, then the replica job should use the more efficient site-local copy, but if the backup copy job is not finished or selects a restore point earlier than some other available restore point in the "source selection" options, then the replica job will use the "source repository" backup for retrieval.

[foggy]

Correct, this is how it is supposed to work.