Anyway to change pool to use the gpt label instead of gptid?

[Jeremy Chadwick]

On Sun, Oct 23, 2011 at 07:01:31PM -0700, Artem Belevich wrote:
> On Sun, Oct 23, 2011 at 6:49 PM, Larry Rosenman <ler at lerctr.org> wrote:
> > On Sun, 23 Oct 2011, Artem Belevich wrote:
> >
> >> On Sun, Oct 23, 2011 at 5:52 PM, Larry Rosenman <ler at lerctr.org> wrote:
> >>>
> >>> Is there any way to convert this setup to use the GPT labels instead of
> >>> the
> >>> the GPT UUID's in zpool status/zpool iostat?
> >>
> >> You can try exporting the pool and then importing it back with "zfs
> >> import -d /dev/gpt"
> >
> > Really hard to do with root on this pool :)
> 
> You may be able to solve that part with LiveCD. I'm still not quite
> sure where device info is kept -- in the pool or in
> /boot/zfs/zpool.cache. ...

Both.

icarus# zpool status data
  pool: data
 state: ONLINE
 scan: resilvered 279G in 1h0m with 0 errors on Thu Aug 11 22:43:38 2011
config:

        NAME        STATE     READ WRITE CKSUM
        data        ONLINE       0     0     0
          mirror-0  ONLINE       0     0     0
            ada1    ONLINE       0     0     0
            ada3    ONLINE       0     0     0

errors: No known data errors

icarus# strings /boot/zfs/zpool.cache | egrep 'ada[13]'
        /dev/ada1
        /dev/ada1
        /dev/ada3
        /dev/ada3

icarus# dd if=/dev/ada1 of=/dev/stdout count=128 | strings | grep 'ada1'
128+0 records in
128+0 records out
65536 bytes transferred in 0.013422 secs (4882725 bytes/sec)
        /dev/ada1
        /dev/ada1

icarus# dd if=/dev/ada3 of=/dev/stdout count=128 | strings | grep 'ada3'
128+0 records in
128+0 records out
65536 bytes transferred in 0.023449 secs (2794838 bytes/sec)
        /dev/ada3
        /dev/ada3

Larry, have you considered avoiding ZFS on root and instead just using
gmirror on your OS partition (not the entire disk, and not the swap
partition)?  I've read that gmirror "just works" and is reliable,
including booting from it, and supports hot spares.

Thought I remember there being some caveat to swap being stored under
gmirror -- the man page mentions caveats that relate to getting kernel
panics/dumps -- so that may be a problem.  Using multiple partitions and
mirroring only the UFS/UFS2 partition sounds like a better choice.

I know it would be ideal to have it all controlled with ZFS, I
understand/hear you (especially since I just got done harping on added
complexity, re: GPT labels vs. device names), but welcome to the mess.

-- 
| Jeremy Chadwick                                jdc at parodius.com |
| Parodius Networking                       http://www.parodius.com/ |
| UNIX Systems Administrator                   Mountain View, CA, US |
| Making life hard for others since 1977.               PGP 4BD6C0CB |