Backup repository concurrent tasks

[kaboomza]

Hi guys,

Can anybody provide some insight or recommendations for how one can properly define or identify the optimal concurrent tasks to configure on a repository level?

[PetrM]

Hi Jacques,

You may refer to this page of our best practices guide, there is a good example for repository server sizing and task slots calculation.

Thanks!

[kaboomza]

Thanks for feedback @Petrm

So based on that page and what you are saying, it would appear that I have a repo that the proxy is hosting, and that proxy has 20 cores for example, I could potentially push the concurrent tasks on the repo side to say 14 based on those calculations? also taking RAM into consideration?

[PetrM]

Hi Jacques,

Yes, it should be fine. Although, it's always worth testing the numbers in your specific environment and probably increase concurrent tasks a bit if it does not produce an additional overhead on the backup storage.

Thanks!

[HannesK]

Hello,
unfortunately that best practice guide has some issues... we are working on updating it.

Everything below and an the best practice guide assumes that it is a dedicated repository server. If you host proxy & repository on the same machine, apply sizing for both roles.

The most conservative rule is 1.5:1 task / cores ratio. Example: if you have 20 cores, that means 30 tasks.
I always recommend to start with 2:1 as customers feedback is "my repo servers idle". That means if you have 20 cores, configure 40 tasks.
If you still see low CPU & RAM load, you can go higher.

For RAM: 4 GB RAM per CPU core.

Best regards,
Hannes

[pirx]

Is this also true for concurrent proxy tasks? We talked about that before. I'm just asking because yesterday I had (again!) a discussion about my concurrent proxy tasks which are set to 30 with 20 core server. perfmon shows no relevant CPU load during backup window (max 30%). He told me that this has nothing to do with the CPU load, it's purely about cores and tasks.

[HannesK]

for proxy, the official best practice is 1:1 core / task ratio. Usually it can be oversubscribed a little bit. I hear that 1.1-1.25 : 1 works fine in many cases (depends also on the version of VBR).

If 1.5:1 works fine for you, then go for it