From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Brown Subject: Re: raid10 on three discs - few questions. Date: Mon, 4 Feb 2008 10:11:27 +1100 Message-ID: <18342.18975.229866.860765@notabene.brown> References: <20080203235043.3dbb6433@szpak> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: message from Janek Kozicki on Sunday February 3 Sender: linux-raid-owner@vger.kernel.org To: Janek Kozicki Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Sunday February 3, janek_listy@wp.pl wrote: > Hi, > > Maybe I'll buy three HDDs to put a raid10 on them. And get the total > capacity of 1.5 of a disc. 'man 4 md' indicates that this is possible > and should work. > > I'm wondering - how a single disc failure is handled in such configuration? > > 1. does the array continue to work in a degraded state? Yes. > > 2. after the failure I can disconnect faulty drive, connect a new one, > start the computer, add disc to array and it will sync automatically? > Yes. > > Question seems a bit obvious, but the configuration is, at least for > me, a bit unusual. This is why I'm asking. Anybody here tested such > configuration, has some experience? > > > 3. Another thing - would raid10,far=2 work when three drives are used? > Would it increase the read performance? Yes. > > 4. Would it be possible to later '--grow' the array to use 4 discs in > raid10 ? Even with far=2 ? > No. Well.... if by "later" you mean "in five years", then maybe. But the code doesn't currently exist. NeilBrown