From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hubert Verstraete Subject: RAID5 initial resync: faster vs more secure Date: Thu, 20 Mar 2008 17:58:19 +0100 Message-ID: <47E297AB.8020001@free.fr> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids Hi list Each time I create a RAID5 array, by default, as a degraded array with a spare, I cannot stop and restart the array unless the initial resync has completed. If I do so, the resync is not resumed when the array is re-assembled. Is this due to the fact that one disk is a spare, but md actually doesn't know which of the disks is the spare one ? Assuming that there is no bug and no workaround about this issue, I think the following: when one cannot guarantee the array won't be stopped until the resync completes, one should better create the RAID5 array with the -f option. Indeed, when I use -f, I can stop the array and restart it, the resync will be resumed where it had stopped. The cost of this is that the initial resync runs slower. Comments are welcome. Thanks, Hubert PS: the reshape patch from Neil on 03/03/08 does not fix the issue.