I installed the OpenZFS on Mac v2.2.2 package for Big Sur 11.7.9, gave it access through the Security Preferences, and rebooted.
I used diskutil to erase an external SSD drive I'm testing with. When I erased the volume, I put Mac OS Extended on it.
I then created a single volume pool on the device.
zpool create -f mypool /dev/disk6s2
I used -f because without it, it complained about the FS already there.
Everything seemed to go fine.
# zpool status mypool
pool: mypool
state: ONLINE
config:
NAME STATE READ WRITE CKSUM
mypool ONLINE 0 0 0
disk6s2 ONLINE 0 0 0
errors: No known data errors
I then tried to copy a 20GB file on my internal drive I had handy using the Finder.
It started copying fine, but then, everything came to a screeching halt.
Most notably, my mouse was unresponsive. I'd move it and it would crawl across the screen. I noticed on the Activity Monitor that both the Read and Write speeds were getting slower and slower, from 100+MB/s down to below 20. After some very careful and patient mouse positioning, I managed to cancel the copy. CPU load was not particularly notable.
The machine went back to its normal responsiveness.
This machine is a 2020 Intel iMac with 72GB of RAM.
A while (year or so) ago I tried ZFS. That time, I created two partitions and tried to mirror them. But, again, performance was terrible. I thought it was because I mirrored to halves of the same physical drive (not a practical solution, but I was just playing around). But this time, it was the whole volume.
If it matters, I'm running a Logitech MX Master 3 keyboard and mouse.
Curious if anyone else has seen anything like this. ZFS is essentially unusable for me because of this.
