[OpenIndiana-discuss] [developer] Badly balanced pool (was Re: Block pointer rewrite?)

[Bayard G. Bell]

On Fri, 2012-01-13 at 09:51 +0100, Roy Sigurd Karlsbakk wrote:
> >> PS: The reason I think of this, is I have a pool which is rather badly balanced
> >> due to a bad combination of little time and (at that moment) little zfs knowledge,
> >> so currently two VDEVs are >95% full, and AFAIK there's no way to fix that except
> >> (a) reconfigure everything or (b) by magick or BPR, which may be similar :P 
> 
> > What problem are you having in particular? My colleague George Wilson has done some
> > work to improve performance on imbalanced vdevs, which may be sufficient for you. 
> > Be sure you are running a build with the fix for 1051 , integrated in May 2011. 
> 
> The issue we're seeing is rather terrible performance, especially during scrub, on this system. It has sufficient amounts of L2ARC (10x256GB) and SLOG (a 100GB mirror) (see attached zpool iostat -v - the mirror with c14t21d0 and c14t22d0 are the SLOG devs). It's still at oi_148, so perhaps just an upgrade to 151 might help? Or will I need to patch the system with later code?

As oi_148 was released before May 2011, it stands to reason you don't
have the fix. As George has been good enough to give the fix ID, you
should be able to see whether the change was committed in 151 by looking
through its log:

http://hg.openindiana.org/sustaining/oi_151a/illumos-gate/shortlog