ZFS Issue or Not

[Big Wig]

Is this common transfer speed for ZFS under these setup parameters.  I have created the following ZFS pools and disks.

 

#1 3-M.2 SSD ZFS Z1 pool (Cache_NVME) with compression

#2 4-HDD ZFS Z1 pool (HDD_Zpool) with compression and encryption

#3 4-Single HDD ZFS formated drives with compression.

 

Rough file transfer results on a 8 Gig movie file:

#1 Cache Pool to #2 HDD Pool=168MBs-220MB/s (Before using XFS is was usually getting 120 MB/s) Great!

#1 Cache Pool to #3 Single ZFS drive= Starts off at 220 MB/s but 30% into the transfer process nose dives into the 30 MB/s range.  Uggg!

 

In short going from Pool to Pool is good for transfer but from pool to single sucks or do I have some sort of issue?

 

Thanks,

[itimpi]

I know there are reports of a speed issue to single ZFS formatted drives in the main array but not heard about it for single drive pools.    Have you checked that none of the HDD concerned are SMR drives (particularly #3) as that could skew your results badly.

[Big Wig]

The single ZFS drive I am testing with is a Toshiba N300 NAS 4 TB Hard Drive and is stated to use CMR.

Thanks,

[Big Wig]

I also tried the following just to make sure it was not the Toshiba drive so i selected a WD drive with same result.  Now im going #4 Single ZFS Drive to #4 Single ZFS drive and getting a 5-10 MB/s. Triple UGGGG!

 

[JorgeB]

There's a known issue with zfs on the array, see here:

https://forums.unraid.net/bug-reports/prereleases/zfs-write-speed-issue-array-disk-no-parity-on-6120-rc6-r2414/