zfs discuss - Nov 2006 - ZFS caught resilvering when only one side of mirror persent

When I booted my laptop up this morning it took much longer than normal 
and there was a lot of disk activity even after I logged in.

A quick use of dtrace and iostat revealed that all the writes were to 
the zpool.

I ran zpool status and found that the pool was resilvering.

Strange thing is that while the pool is a mirror, one side of it is 
offline since it is on an external usb disk - which is the same size as 
the slice on my laptop internal disk that contains the pool.

So what was ZFS resilvering ?

This is the config of the pool.  I earlier showed that it was resilvering.

$ zpool status
   pool: local
  state: DEGRADED
status: One or more devices has been taken offline by the adminstrator.
         Sufficient replicas exist for the pool to continue functioning in a
         degraded state.
action: Online the device using ''zpool online'' or replace the
device with
         ''zpool replace''.
  scrub: resilver completed with 0 errors on Thu Nov 30 10:08:23 2006
config:

         NAME        STATE     READ WRITE CKSUM
         local       DEGRADED     0     0     0
           mirror    DEGRADED     0     0     0
             c2t0d0  OFFLINE      0     0     0
             c0d0s7  ONLINE       0     0     0

errors: No known data errors

-- 
Darren J Moffat