From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Leslie Rhorer" Subject: RE: How to un-degrade an array after a totally spurious failure? Date: Mon, 8 Jun 2009 20:55:51 -0500 Message-ID: <20090609015548401.RETS26412@cdptpa-omta03.mail.rr.com> References: <18989.3642.996238.323569@fisica.ufpr.br> Reply-To: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <18989.3642.996238.323569@fisica.ufpr.br> Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids > >> > Leslie Rhorer (lrhorer@satx.rr.com) wrote on 7 June 2009 20:43: > >> > >OK, what about a RAID 6 array with one failed disk? Is the remove > & add > >> > >the best option there, or should one apply a different method? > >> > > >> > It is, since that's what the raid is for. It's still operational. > >> > We've done it here and it works. > >> > >> Well, yes, I know it should work. The question is, "Is it the best > method?" > > I don't understand what you mean. It is the only method. We've discussed others, here, including stopping the array and doing an assemble --force. I think re-add will also work, won't it? > Everything > should be perfectly fine because of the redundancy. You only have to > do tricks when you have more failed disks than the array supports, > which always involves a certain risk. If there are other "tricks", then by definition a remove followed by an add is not the only possible method. I can certainly accept it is the best one, but I was not certain of it, which is why I asked. OF course, one can define "best" in a number of ways, but I would say the fastest recovery method that still maintains data integrity is the best. The add + resync is not exactly fast.