zfs discuss - Jul 2008 - Adding slices from same drive to a pool

I''d like to extend my ZFS root pool by adding the old swap and root
slice
left over from the previous LU BE. 

Are there any known issues with concatenating slices from the same drive? 

Cheers, 

Ian.

Ian Collins wrote:
> I''d like to extend my ZFS root pool by adding the old swap and
root slice
> left over from the previous LU BE. 
> 
> Are there any known issues with concatenating slices from the same drive? 
Having done this in the past (many builds ago) I found the performance 
wasn''t good.  It is really bad if you tried to mirror between different
slices of the same drive (use copies=2 instead).

If the old swap and root slices are after the ZFS root pool then you 
should be able to use format to delete them and add them onto the end of 
the slice the pool is in.  If they are before it then I think you are 
out of luck.

If they are before the ZFS root pool one possible thing you might be 
able to do would be to boot failsafe (which runs compeltely from RAM) 
then making sure the pool as NOT imported use some dd to shift the stuff 
(overlaping slices might help with this).  But I''d make sure you have a
full and verified backup before trying that.  Note that I''ve not tried 
this myself but I might be tempted to give it a go on my OpenSolaris 
2008.05 (upgrade to snv_93) system since it has swap as a separate slice 
at the start of the disk.

-- 
Darren J Moffat