From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomasz Chmielewski Subject: Re: how to synchronize two devices (RAID-1, but not really?) Date: Tue, 15 May 2007 12:36:36 +0200 Message-ID: <46498D34.1060901@wpkg.org> References: <4649760A.1060805@wpkg.org> <17993.34959.150157.200536@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: <17993.34959.150157.200536@notabene.brown> Sender: linux-raid-owner@vger.kernel.org To: Neil Brown Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids Neil Brown schrieb: (...) > You will want to test this of course - I cannot guarantee that I have > that command exactly right. > > If the remote device fails (link breaks) it should get marked faulty > in the array. Once you have it working again you can use mdadm to > remove (--remove) and re-add (--re-add) the device. It should > complete the copy correctly. You should test that this actually > works as expected. > > Feel free to ask questions if you choose to attempt this route. Interesting lecture, thanks a lot. I'm gonna take that path. I have one more question, though. I want to migrate: - from 4x400GB HDD RAID-10 - to 4x400GB HDD RAID-5 Obviously, I need 8 disks for that, but I have only 6. So my idea was to kick one disk from RAID-10, and use it for RAID-5 for the time of migration. This means, I would have only 3 disks out of 4 in RAID-5 array. Is it possible to create a degraded, 4 disk RAID-5 array with just 3 drives? I would add the 4th drive once migration from RAID-10 is done. (I'm aware of the risks - that my degraded RAID-10 will be "vulnerable" during the migration). -- Tomasz Chmielewski http://wpkg.org