Concurrent tasks on esata repository

[Nicholasbird]

i have a single 12tb esata drive as a repository/target. and a single job with 30 vms.
source is an all flash 4 node vsan supported by 4 backup proxies (1 per node).
would the default 4 concurrent tasks on the esata repository mean that (up to ) 4 vms are being written to disk concurrently.
given sata will typically perform best with 1 sequential operation at a time
(4 in series rather than 4 in parallel)
would a setting of 1 concurrent task generally be best for an esata single disk repository?
one concurrent write operation seems sensible for most spinning disks and yet the default is 4 , so i feel i am missing something.
thanks

[HannesK]

Hello,
looks like the environment is undersized from a restore perspective - I hope you never need to restore quickly...

as you have one single job, the streams depends whether you have per-vm backup files or not. Per default it's a per-job chain, so you have one stream.

The the tasks in general are about disks: https://helpcenter.veeam.com/docs/backu ... l?ver=95u4

As a single spinning disk has literally no performance, I can add two recommendations for that
- use active full backups
or
- format with REFS


Best regards,
Hannes

[Nicholasbird]

Hi Hannes,
thanks for feedback,
I think you are being a bit harsh on esata's performance, we can restore at 200MB/s but we do admittedly have fairly relaxed RTOs
we are using active full back ups on NTFS (we only use the disk once for one backup, before it is formatted when reused)
we are not using per vm backup files as the repository is backed by rotating disks

So to spell it out, in our scenario, are you suggesting that we should expect best performance setting concurrent tasks to 1?

thanks
Nick

[HannesK]

Hi,
yes 1 is fine.

eSATA is fine, I'm more worried about the spinning disk

Yes, you can do 200 MByte for the full right now... did you try with an incremental chain? Then you need to read from multiple files and it is not fully sequential anymore. So I expect speed to be significantly slower.

Anyway: if you are happy with the restore speed, then it's fine

Best regards,
Hannes