On Oct 20, 2010, at 2:24 AM, Tuomas Leikola wrote: > On Tue, Oct 19, 2010 at 7:13 PM, Roy Sigurd Karlsbakk <r...@karlsbakk.net> > wrote: >> I have this server with some 50TB disk space. It originally had 30TB on WD >> Greens, was filled quite full, and another storage chassis was added. Now, >> space problem gone, fine, but what about speed? Three of the VDEVs are quite >> full, as indicated below. VDEV #3 (the one with the spare active) just spent >> some 72 hours resilvering a 2TB drive. Now, those green drives suck quite >> hard, but not _that_ hard. I'm guessing the reason for this slowdown is the >> fill of those three first VDEVs. >> >> Now, is there a way, manually or automatically, to somehow balance the data >> across these LVOLs? My first guess is that doing this _automatically_ will >> require block pointer rewrite, but then, is there way to hack this thing by >> hand? > > > I described a similar issue in > http://opensolaris.org/jive/thread.jspa?threadID=134581&tstart=30. My > solution was to copy some datasets over to a new directory, delete the > old ones and destroy any snapshots that retain them. Data is read from > the old device and written on all, causing large chunks of space to be > freed on the old device. > > I wished for a more aggressive write balancer but that may be too much > to ask for.
This can, of course, be tuned. Would you be interested in characterizing the benefits and costs of a variety of such tunings? -- richard -- OpenStorage Summit, October 25-27, Palo Alto, CA http://nexenta-summit2010.eventbrite.com USENIX LISA '10 Conference, November 7-12, San Jose, CA ZFS and performance consulting http://www.RichardElling.com _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
