Hi,
I have a 10 disk raidz2 pool on 10.11.3 which was recently upgraded to 1.4.5
It seems to work fine, but iTunes is struggling. I keep the library files on an SSD in my home folder, but iTunes is directed to the media on the ZFS volume. This worked fine before, but upgrading to 10.11.3 and 1.4.5 seems to have broken it. Basically it is very slow at writing. When I try to import an album, iTunes will fail and say "The required file cannot be found" or somesuch.
When writing a large file, speed can be 150MB a second or faster, but that is hardly scientific.
Any ideas?
Edit:
This seems to be the bug: https://github.com/openzfsonosx/zfs/issues/394 as I see plenty of "27/01/2016 8:54:00.356 PM iTunes[20740]: Possible unresolved transaction race -105"