Question about mirror backups
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Last friday we got the first version of filtering on mirror backups, we were waiting for this feature for a long time and in general it does what is promises. I believe it needs some polishing but knowing Vates this will be done!
We are now testing this with one repository and i run into an issue, when we create a mirror job for 3 vms on a repository and i start this job the performance of any running backup job to this repository colapses from 15min to several hours (8 to 10), it seems like the reads from the repository are slowing things down. We do use NFS V4.1 on synology boxes in this case with around 12 disks (HDD 7200rpm), normally backups are fast but these 2 are killing each other. I was thinking could this be an issue with NFS settings or other protocol settings? In general we do not see any performance related issues with multiple backup jobs at the same time. In general it feels like reading is killing the writes.
hope anyone can help us in the right direction.
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These are the nfs settings we do currently have set on this target
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It's probably that your BR can't keep up with the IOPS. Mirror backup will only read, but it can read a lot if there's a lot of data to mirror.
Can you try do a mirror first without other backup running on the BR at the same time? To me, the symptom is simply a BR that's not able to keep up.
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@olivierlambert yes i will check this out as well. The mirror job itself seems to perform well, i changed the nfs to V3 as a first test for now, i read there is more overhead on V4, maybe this will improve things a bit. I will share the results!
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@olivierlambert i have changed it to V3 and it feels like it is performing normally now. i need to do some more testing but it seems the synology does handle the read/writes better on V3 then V4.
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@olivierlambert moving it to NFS v3 did the trick, no more performance dips when we run mirrors. So if anyone does run into the same issue, try changing this setting on synology, i hope that will help!
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I wonder what's causing this
So it's like NFSv4 is crippling the BR perfs right? Are you seeing any diff in mirroring job speed? -
@olivierlambert nope not at all. i have a feeling that it's not the disks but more like the overhead on cpu of that boxes. V3 is more lightweight.
