From mboxrd@z Thu Jan 1 00:00:00 1970 From: "exxs.net - matevz sernc-urban" Subject: RAID10,f2 out of sync though synced Date: Fri, 25 Jul 2008 13:18:02 +0200 Message-ID: <4889B66A.20301@exxs.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; 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 Hello, we have a RAID10,f2 over 4 SATA drives connected directly to the mobo. Comparing a md5sum on first 1K (or 1M) gives me two different md5 - sometimes its '0f343b0931126a20f133d67c2b018a3b' and other times its 'eff670f7076825ba3411ec24dd1ea5b1'. Is this a correct behaviour on a RAID10,f2 with 4 disks? And hints? * cat /proc/mdstat Personalities : [raid1] [raid10] md2 : active raid10 sdb5[1] sda5[0] sdd5[3] sdc5[2] 953778688 blocks 64K chunks 2 far-copies [4/4] [UUUU] * echo check > /sys/block/md2/md/sync_action finished without any new result - then array must be in sync i suppose. * did also: echo 1 > /proc/sys/vm/drop_caches * and now we compare the first 1K from the array - it should always be the same, but its not. => dd if=/dev/md2 iflag=direct bs=1K count=1 status=noxfer|md5sum 0f343b0931126a20f133d67c2b018a3b => dd if=/dev/md2 iflag=direct bs=1K count=1 status=noxfer|md5sum eff670f7076825ba3411ec24dd1ea5b1 => dd if=/dev/md2 iflag=direct bs=1K count=1 status=noxfer|md5sum eff670f7076825ba3411ec24dd1ea5b1 => dd if=/dev/md2 iflag=direct bs=1K count=1 status=noxfer|md5sum 0f343b0931126a20f133d67c2b018a3b thanks mat