From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Tran Subject: Re: EVMS or md? Date: Mon, 04 Apr 2005 18:03:33 -0500 Message-ID: <1112655813.7245.10.camel@langvan2.homenetwork> References: <200504040708.j3478bm03863@www.watkins-home.com> <1112642928.25469.28.camel@dyn95395156> <200504041446.50337.kewley@gps.caltech.edu> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Mon, 2005-04-04 at 17:15, H. Peter Anvin wrote: > Followup to: <200504041446.50337.kewley@gps.caltech.edu> > By author: David Kewley > In newsgroup: linux.dev.raid > > > > Mike Tran wrote on Monday 04 April 2005 12:28: > > > We (EVMS team) intended to support RAID6 last year. But as we all > > > remember RAID6 was not stable then. I may write a plugin to support > > > RAID6 soon. > > > > Hi Mike, > > > > In your view, is RAID6 now considered stable? How soon might you have an evms > > plugin for it? ;) I'd love to use evms on my new filserver if it supported > > RAID6. > > I will do it, but I can't promise a time frame. I will announce on evms mailing list when it's available. This discussion should be on evms mailing list (sorry folks!) > > I can't speak for the EVMS people, but I got to stress-test my RAID6 > test system some this weekend; after having run in 1-disk degraded > mode for several months (thus showing that the big bad "degraded > write" bug has been thoroughly fixed) I changed the motherboard, and > the kernel didn't support one of the controllers. And now there were > 2 missing drives. Due to some bootloader problems, I ended up > yo-yoing between the two kernels a bit more than I intended to, and > went through quite a few RAID disk losses and rebuilds as a result. > > No hiccups, data losses, or missing functionality. At the end of the > whole ordeal, the filesystem (1 TB, 50% full) was still quite prisine, > and fsck confirmed this. I was quite pleased :) > > Oh, and doing the N-2 -> N-1 rebuild is slow (obviously), but not > outrageously so. It rebuilt the 1 TB array in a matter of > single-digit hours. CPU utilitization was quite high, obviously, but > it didn't cripple the system by any means. > Glad to hear the good news :) mdadm or EVMS is just a user space tool. We depend on the kernel side to provide stability. -- Mike T.