6.12 Slow ZFS Writes in Array

[whitephoenix117]

I added a new ZFS drive to my pool and started to move data over, its quite slow. Drive should be between 150-250 MB/s but its been hovering at +/- 50. There seems to be something bottlenecking a 1 or 2 single cores, screenshot below shows just 1 but sometimes its 2.

 

 

 

 

 

Edited June 18, 2023 by whitephoenix117
add screenshot

[JorgeB]

That looks about right with default writing mode, you can try turbo write, should be faster at the expense of all drives spinning up for writes.

[whitephoenix117]

6 hours ago, JorgeB said:

That looks about right with default writing mode, you can try turbo write, should be faster at the expense of all drives spinning up for writes.

 

Thanks!

 

Sure enough enabling reconstruct write did improve the speed. The parity delay mentioned is not unique to ZFS but it I have never noticed it before so then:

• When I looked at write speeds the past all the disks happened to already be spun up
•  The effect is somehow worse with ZFS?

 

 

[JorgeB]

9 hours ago, whitephoenix117 said:

The effect is somehow worse with ZFS?

It's no different with zfs.