From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomasz Chmielewski Subject: Re: Linux RAID migration Date: Tue, 07 Aug 2007 12:37:39 +0200 Message-ID: <46B84B73.6090803@wpkg.org> References: <5b170a7d0708070126t52cb4be5x4549b22bac643450@mail.gmail.com> <18104.18410.623573.929770@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <18104.18410.623573.929770@notabene.brown> Sender: linux-raid-owner@vger.kernel.org To: Neil Brown Cc: saeed bishara , Tuomas Leikola , linux-raid@vger.kernel.org List-Id: linux-raid.ids Neil Brown schrieb: (...) >>>> - can I really assume that RAID 5 on 2 hdds (degraded mode) will >>>> function as raid 5? >>> You should test by using loopback devices and files. But why degraded? >>> raid5 of two disks should look like raid1. >> I meant to ask whether raid 5 on 2 disks will function as raid1 :( > > A 2-disk raid5 and a 2-disk raid1 put the data in exactly the same > place - is that what you wanted to know? Is the same valid for RAID-10? Let's say, you degraded a 4-disk RAID-10 to just 2 (proper) disks. Then, you want to migrate it to 2-disk, 3, 4, and eventually, 5-disk RAID-5 array. Would the RAID-10 -> RAID-5 migration be as easy as in RAID-1 -> RAID-5 case? -- Tomasz Chmielewski http://wpkg.org