Recommended quantity of verification readers / workers

[Taledo]

Hi all,

Since 4.0 (I think?) you can tweak the number of readers & workers for the verify job.
I've set mine to 12 workers and 4 readers, and it cut the verification times by half. Do keep in mind this is a NVMe backed ZFS system, YMMV.

Are there good practices to set those values? Do you have feedback on larger datasets? I only have around 50Tb of data.

Regards,

Taledo

 

[Johannes S]

I would set both to the number of CPU cores on the server. YMMV

 

[Taledo]

An update on this :
The maximum for both values is apparently 32.
I'd need more benchmarks to plot some kind of "time reduction per worker", but setting the values to 12 workers and 4 readers has brought down the verify time from around 10h to ~4h. Bringing the numbers up to the maximum value reduces the verify time to around ~3h - 3h30, so there might be less gained from doing that.