ZFS: drive replacement performance

[Jonathan]

On 7/7/2009 8:13 PM, Mahlon E. Smith wrote:
> I also tried another export/import cycle, in the random hope that would
> stop the active replace -- no dice.  *However*, on the import, now I see
> this flooding my console (wasn't there previously, strangely):
>
> Jul  7 16:50:15 disobedience root: ZFS: vdev I/O failure, zpool=store path=/dev/da2 offset=262144 size=8192 error=6
> Jul  7 16:50:15 disobedience root: ZFS: vdev I/O failure, zpool=store path=/dev/da2 offset=499988824064 size=8192 error=6

I actually just had this exact issue with a dead drive, controller 
renumbering, and vdev I/O failure.  I eventually shut the system down 
completely, pulled the new drive, checked all the drive connections, 
powered the machine back up without the new drive.  Then I inserted the 
new drive and initiated a scan for it.  Apparently ZFS doesn't realize 
when a resilver is partially done because it resilvered in a matter of 
seconds at this point.  I then did a scrub which found several million 
checksum errors but successfully corrected the pool without any vdev I/O 
failure errors.

I hope this helps,
Jonathan Stewart