On Fri, Jan 6, 2012 at 8:53 AM, Roy Sigurd Karlsbakk <r...@karlsbakk.net> wrote:
> > Some time back, perhaps 2-3 years ago, I first heard someone mention > Block pointer rewrite (BPR) and what could be done with that. Is it, from > the Illumos developers point of view, likely that this will ever see the > day? As far as I can understand, S11 doesn't have this, but I thought I > heard certain parts of it was written. I implemented most of BP rewrite several years back, at Sun/Oracle. I don't know what plans Oracle has for this work, but given its absence in S11, I wouldn't bank on it being released. There are several obstacles that they would have overcome. Performance was a big problem -- like with dedup, we must store a giant table of translations. Also, the code was didn't layer well; many other features needed to "know about" bprewrite. Maintaining it would add significant to cost to future projects. > 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<https://www.illumos.org/issues/1051>, integrated in May 2011. --matt ------------------------------------------- illumos-discuss Archives: https://www.listbox.com/member/archive/182180/=now RSS Feed: https://www.listbox.com/member/archive/rss/182180/21175430-2e6923be Modify Your Subscription: https://www.listbox.com/member/?member_id=21175430&id_secret=21175430-6a77cda4 Powered by Listbox: http://www.listbox.com
