OpenZFS on OS X

I've been fiddling around with a fresh install of Sierra 10.12.1 and a newly compiled ZFS (1.5.2), to get a sense of stability, as I've been running the existing installer 1.5.2 with Sierra for awhile, under minimal load on the pool. That's all background however. I thought I'd check out the new APFS and got this when I fired up Disk Utility:



Haven't tried it out yet, wondering if anyone else has seen it, and if it might be related to/confused by APFS?

Well, thought I'd give it a go - step off the cliff so to speak. Macintosh HD being one of two HFS+ Journaled partitions on an internal disk. Result being that it failed to complete the initialisation:

Unmounting disk
Erasing
argv[0]: /Library/Filesystems/zfs.fs/Contents/Resources/zfs.util

argv[1]: -v
argv[2]: Untitled
argv[3]: /dev/rdisk0s2
zfs.util called with option v

Mounting disk
Could not mount disk0s2 after erase
File system formatter failed.
Operation failed…

sudo zpool import -a doesn't show it up as a pool, and it still appears in Disk Utility as an Untitled partition of the disk. Running the erase on that a second time creates an unnamed partition described as an Uninitialised ZFS Dataset. All of this appears to have no negative consequences on the other partition on the disk. Diskutil list shows up as follows:

192-168-1-2:~ sadmin$ diskutil list
/dev/disk0 (internal, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *500.1 GB disk0
1: EFI EFI 209.7 MB disk0s1
2: ZFS 248.1 GB disk0s2
3: Apple_HFS SierraServerClone 250.5 GB disk0s4
4: Apple_Boot Recovery HD 650.0 MB disk0s5

I'll fool around further and see what happens.

I believe by having a fs.bundle we can add ourselves to diskutil but I've never seen to show up before so that is interesting. For it to actually work, we need to add a bit more logic to zfs.util in the bundle to actually call zfs create.

It's showing up for me to.
Got me wondering a bit since I haven't installed anything to do with ZFS for a while.

Checked back in El Capitan in case I missed it, but its definitely not there. Shows up in latest Sierra with installer version 1.5.2

Neat, so we'd better add some code and get that working, incase people use it thinking it will do something