From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben DJ Subject: Re: A few remaining questions about installing to RAID-10 Date: Fri, 2 Oct 2009 09:31:07 -0700 Message-ID: References: <887103.5263.qm@web38801.mail.mud.yahoo.com> <20091002151504.GA22207@cthulhu.home.robinhill.me.uk> <20091002155919.GB22207@cthulhu.home.robinhill.me.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20091002155919.GB22207@cthulhu.home.robinhill.me.uk> Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org, robin@robinhill.me.uk List-Id: linux-raid.ids Hi, On Fri, Oct 2, 2009 at 8:59 AM, Robin Hill wrot= e: > Either 0.90 or 1.0 will work (both are held at the end)- 0.90 allows = for > kernel auto-assembly, but is a legacy format. =A0Any modern Linux > distribution will use an initrd which can assemble arrays with any > superblock, so current advice would be to use 1.0. Ok, that's clear. > For a boot partition I'd stick with RAID-1, then use RAID-10,f2 for > other partitions. f2 is clear for read-mostly space, like most of /root. But for /var? /home? other /data? I'm learning there a 'subtleties' to all this. > There's no real advantage in using RAID-10,n4 over > RAID-1 (it's a different code-path so there may be slight differences > one way or the other, but nothing that will matter for a boot > partition anyway), and just makes the setup more unusual. I thought that RAID-10's disk failure survivability is n-2, for n >=3D4 drives. RAID-1 over 4 drives can also survive 2-drive failure? > It's up to you though - RAID-10,n4 and a four-way RAID-1 will have th= e > same on-disk layout, so either will work fine. =A0Oh - one other thin= g is > that RAID-1 is expandable (you can add other partitions later) wherea= s > RAID-10 is not currently. Athough needing to expand /boot is hardly a requirement, I did NOT realize that RAID-10 is not expandable. Partitions ARE certainly add-able within the LVM that spans the RAID-10, but I thoguth that spindles, and new partition could be added after initial creation. Need to read some more. Ben -- To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html