[OpenIndiana-discuss] ZFS pool slow as molasses

[Brett Dikeman]

On Tue, Oct 5, 2010 at 5:42 PM, Paul Johnston
<Paul.A.Johnston at manchester.ac.uk> wrote:

> I have a Dell Optiplex 755 and when I switched in the bios from ATA to AHCI
> it wouldn't boot so I'll get another disk and do a re-install then I can

It's actually pretty easy; googling 'round: boot off the OpenIndiana
LiveCD (if you've upgraded to a higher ZFS version than OpenSolaris
supports) and import the system pool.  This fixes the device names
stored inside the pool (?) metadata:

http://wstrange.wordpress.com/2010/04/27/opensolaris-tip-switching-from-ide-to-ahci-driver/

I burned the DVD, booted off it with the system in AHCI mode, and
imported the system (rpool) ZFS pool, and did the same with "data".
While the system booted, the data pool wasn't recognized:

# zpool status
  pool: data
 state: UNAVAIL
status: One or more devices could not be opened.  There are insufficient
        replicas for the pool to continue functioning.
action: Attach the missing device and online it using 'zpool online'.
   see: http://www.sun.com/msg/ZFS-8000-3C
 scan: none requested
config:

        NAME         STATE     READ WRITE CKSUM
        data    UNAVAIL      0     0     0  insufficient replicas
          raidz1-0   UNAVAIL      0     0     0  insufficient replicas
            c7d1p0   UNAVAIL      0     0     0  cannot open
            c8d0p0   UNAVAIL      0     0     0  cannot open
            c8d1p0   UNAVAIL      0     0     0  cannot open
            c10d0p0  UNAVAIL      0     0     0  cannot open

The solution for that was to run:
zpool export data
zpool import -f data

...and then reboot, because I got:

cannot mount 'data': mountpoint or dataset is busy

Performance of the scrub is still in the 100-200KB/sec rnage, so the
original complaint remains.  Something's wrong.

-B