Re: ZFS - mounting filesystems (Was CVS commit: src/etc)

[Simon Burge <simonb%NetBSD.org@localhost>]

Lots of interesting discussion!  Thanks all.

Broadly I think I can summarise to the following options:

 1. The existing critical_filesystems_zfs rc.conf variable, which
    mixes ZFS configuration in both rc.conf and with ZFS itself.
 2. Add ZFS "critical" properties for filesystems and mount those
    in /etc/rc.d/mountcritlocal .
 3. Move all ZFS mounts to /etc/rc.d/mountcritlocal .
 4. Optionally move all ZFS mounts to /etc/rc.d/mountcritlocal
    controlled by an rc.conf variable (eg zfs_critical).
 5. Move all local mounts to /etc/rc.d/mountcritlocal (ala
    FreeBSD) and possibly rename this to /etc/rc.d/mountlocal .
 6. "Intelligent" ordering based on prefixes, tsort, etc.

In terms of what to do for the up-and-coming netbsd-10 (although the
actual release will still be a little whiles away), I think there
appeared to be broad concensus on that option 2 was reasonable.  I will
try to get an implementation of that ready.  If that's not ready in time
for netbsd-10 I think option 4 is probably least intrusive fallback
especially because it's optional.

critical_filesystems_zfs is still available now, and will be available
going forward.

Option 3 doesn't seem to buy anything if option 4 is available and
option 5 seems like it could be more impactful to existing mixed local
and NFS setups.

Option 6 I think is out of scope of what I want to get root-on-ZFS
working.  That doesn't stop others from fleshing this out of course!

Thoughts?  Anything I've missed?



And somewhat related that came out of this discussion - add a "noerror"
or "notfatal" or some similar keyword that says a failed fsck or mount
doesn't automatically fail the boot and fall back to single user mode.
Although Ignatios had an interesting solution to this with "noauto" and
using @reboot crontab entries.

This seems like a useful idea.  Anyone up for implementing it? :)

Cheers,
Simon.