Apple

mds only really works if mounted with diskutil? Currently, we mount ZFS
with regular mount(2) call, and not via diskutil and Disk Arbitration.
Would a HFS+ filesystem mounted with mount(2) also fail with mds? Should we
create a fs.bundle, with zfs.util -k to reply with a UUID for DA, and use
diskutil to mount?

The mount command does not make the new mount available as a new volume to OSX, AFAIK. Only diskutil / diskarb do that.

2. I can confirm that. I noticed that if you don't use Disk Arbitration then Spotlight won't notice your volume every time, so I needed to use DA to mount our volumes.

And mfs relies on volumes. In fact, mds also relies on fsevents, in order to learn of file changes. It might well be that mount does not invoke fsevents to make mds aware of the new node. Just guessing here, again, though.

Yes, AFAIK mds relies on fsevents but they are posted at the end of the relevant syscalls. So the local filesystems get this feature for free. It is different game for network filesystems, though.

3. I speculated that if I mark the mount with MNT_DOVOLS flag then mds will expect the fs to provide persistent object IDs between mounts, but our fs didn't have such feature, so after disabling this flag mds liked us.

Hope this helps. Good luck!

Alex

[1] http://fstools.macosforge.org/trac/browser/trunk/src/fsx

References:
	>Seeking cooperation from mds and Spotlight (From: Jorgen Lundman <email@hidden>)
	>Re: Seeking cooperation from mds and Spotlight (From: Thomas Tempelmann <email@hidden>)