ZFS on current vs wedges - best practice?

[Jeff Rizzo <riz%tastylime.net@localhost>]

I had forgotten about this little detail, and am not sure about the best 
way to deal with it.


I have four disks partitioned with GPT (so I can create a raidframe 
raid1 on part of the disk, and use the rest for ZFS), and I made the 
mistake (?) of using wedge names to create the zpool.  So, after a 
reboot (but not the first time! only happened after n reboots), the 
wedges reordered themselves, and now my zpool looks like this:


    NAME                      STATE     READ WRITE CKSUM
    tank                      UNAVAIL      0     0     0
      raidz2-0                UNAVAIL      0     0     0
        3140223856450238961   UNAVAIL      0     0     0  was /dev/dk4
        1770477436286968258   FAULTED      0     0     0  was /dev/dk5
        11594062134542531370  UNAVAIL      0     0     0  was /dev/dk6
        dk7                   ONLINE       0     0     0


I _ think_ I can figure out how to recover my data without recreating 
the entire pool.  (I hope - suggestions there welcome as well!  Once I 
recover this time, I'm going to have to replace the vdevs one at a time 
anyway because I just realized they wedges are misaligned to the 
underlying disk block size.  Sigh.)


However, I'm not sure the best way (is there a way?) to keep this from 
happening again.  Can I use wedge names? (Will those persist across 
boots?)  Other than this minor detail, I've been quite happy with ZFS in 
9 and -current.