From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keld =?iso-8859-1?Q?J=F8rn?= Simonsen Subject: Re: Docs and operation of RAID10, size limitations on 0.90 Date: Wed, 30 Jul 2008 20:29:07 +0200 Message-ID: <20080730182907.GB10710@rap.rap.dk> References: <20080728143553.GE30681@nexus.edgeofthenet.org> <4890943E.5060608@tmr.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Return-path: Content-Disposition: inline In-Reply-To: <4890943E.5060608@tmr.com> Sender: linux-raid-owner@vger.kernel.org To: Bill Davidsen Cc: Richard Michael , linux-raid@vger.kernel.org List-Id: linux-raid.ids On Wed, Jul 30, 2008 at 12:18:06PM -0400, Bill Davidsen wrote: > Richard Michael wrote: > >Hello list, > > > >I'm building a new system with 8 disks, in two RAID5 arrays of 4 disks > >each, and a RAID1 array across them. (Then LVM2 on top of the RAID1 > >array.) > > > >I approached it this way for two reasons: > > > >1/ It feels "cleanest"; in the sense that it's not a special case, it's > >just RAID1 with two devices, which happen to be RAID5. To me it seems muddy. Just having one big raid5 or raid10 would be cleaner and give better performance. > >2/ I have a particular usage in mind: I need to be able to split the > >mirror and remove half; return it later and resync. Therefore, I want > >to know which disks comprise which halves. I am not sure what you mean with this. You want to remove half of the disks? I think you can do that with raid10, you just remove every other disk. I have not tried that out, however. You could try it out before actually emplouing it. > >However, I'm rethinking toward RAID10. However, I can't find much > >documentation about layout, etc. I believe this was recently discussed > >on the list. There is documentation on http://linux-raid.osdl.org/ and on http://std.dkuug.dk/keld/stripemirror.html (for raid10,f2), and on http://en.wikipedia.org/wiki/Non-standard_RAID_levels Best regards keld