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OpenZFS extreme slow on MacBookPro with M1 Max

PostPosted: Fri Aug 05, 2022 4:50 am
by SvenCarstensen
Hello all,

I am trying to use ZFS on a MacBook Pro with M1 Max CPU.
I have installed ZFS the package for the M1 for Big Sur (viewtopic.php?f=20&t=3619, OpenZFSonOsX-2.1.0-Big.Sur-11-arm64.pkg).
The pool was set up with four SSDs as follows:
zpool create -f -o ashift=12 -O casesensitivity=insensitive -O normalization=formD ZFS raidz /dev/disk8 /dev/disk9 /dev/disk10 /dev/disk11
The SSDs are mounted in an external Thunderbolt 3 enclosure.

So far everything looks correct, but writing is very slow with about 80MB/s.
Has anyone else had this problem?

Thanks a lot for your help!

Until then

Sven

Translated with http://www.DeepL.com/Translator (free version)

Re: OpenZFS extreme slow on MacBookPro with M1 Max

PostPosted: Sat Aug 06, 2022 2:28 am
by jawbroken
I have a very similar setup (with regular hard drives, not SSDs, and on Monterey) and I don't see the same performance issues as you. I can write to a 6 disk RAIDZ at 300 or 400 MB/s.

Re: OpenZFS extreme slow on MacBookPro with M1 Max

PostPosted: Sat Aug 06, 2022 9:31 am
by FadingIntoBlue
So far everything looks correct, but writing is very slow with about 80MB/s.
Has anyone else had this problem?


4 disk HD pool - mirrors not raidz, Thunderbolt 2, larger files R/W in the 260-350 MB/s range - though on older zfs version when tested

One thing I have seen, but not tested, is that with SSD ashift value should be 13?
Other thing worth testing is a cable swap.

Small file performance is not as good as GB+ size files for reading, better for writing, peaked at about 520 MB/s

The below article is a very thorough overview of performance issues with different storage structures and parameters

Hope some of that is helpful

https://arstechnica.com/information-technology/2020/05/zfs-101-understanding-zfs-storage-and-performance/?all=1

Just remembered one other thing that made a big difference in my testing, available RAM
Above figures were with the pool attached to my Mac mini with 64GB ram, same mini with only 8GB RAM the R/W rates were about 30%/40% of the above