From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Dragon" Subject: Possible to rescue SW Raid5 with 2 missing Disks Date: Sun, 10 Feb 2013 22:27:32 +0100 Message-ID: <20130210212732.310290@gmx.net> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Return-path: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids Hello, i want to ask again for more help its importan for me and very urgent. I think the moosefs cluster doesnt play a role, because its only a file and directory structure but no real filesystem. this is ext4. i cant believe that a 4 second time out of a raid5 creates such a damage. i had no file write jobs at this time. please help Many thx. sunny -------- Original-Nachricht -------- Datum: Fri, 08 Feb 2013 10:17:00 +0100 Von: "Dragon" An: linux-raid@vger.kernel.org Betreff: Possible to rescue SW Raid5 with 2 missing Disks Hello, my situation is this: i have 3 server with each of 6x3tb in an sw raid5 on a debian squeeze system. on top of this i use moosefs as a filecluster. the problem now is that for a very short time 2 of the disks failed. at this time there was no file activity only the filesync between the nodes of the cluster. after that i cant rebuild the raid: "mdadm: /dev/md2 assembled from 4 drives and 1 spare - not enough to start the array." the superblock seems to be ok. and at least, by an advice from phil turmel, i tried a diffent kind of recreation with these results: Test1: mdadm --create --level 5 -n 6 --chunk=512 --assume-clean /dev/md2 /dev/sd{a,b,c,d,e,f}4 -> filesize 708MB with 20603326 lines and canceling at the end by e2fsck - bad superblock or partitiontable is damage - bad checksum of group or descriptor - lots of invalid inodes - canceld with lots of illegal blocks in inodes Test2: mdadm --create --level 5 -n 6 --chunk=512 --assume-clean /dev/md2 /dev/sd{a,b,c,d,e}4 missing -> filesize 1,3GB with 37614367 lines and canceling by e2fsck at the end - back to original superblock - bad superblock or damaged partitiontable at the beginning - lots of invalid inodes - canceld with iteration of inade Test3: mdadm --create --level 5 -n 6 --chunk=512 --assume-clean /dev/md2 /dev/sd{a,b,c}4 missing /dev/sd{e,f}4 -> filesize 1,4GB with 40745425 lines and canceling by e2fsck at the end - errors see test2 - read error while reading next inode Test4: mdadm --create --level 5 -n 6 --chunk=512 --assume-clean /dev/md2 /dev/sd{a,b,c,f,e,d}4 ->filesize 874MB with 25412000 lines and break by e2fsck at the end - try original superblock - bad superblock or damaged partitiontable - than lots of checksumm invalid deskriptor of group - at the end illegal block in inode to much invalid blocks in inode Test5: mdadm --create --level 5 -n 6 --chunk=512 --assume-clean /dev/md2 /dev/sd{a,b,c}4 missing /dev/sd{e,d}4 -> filesize 1,6GB with 45673505 lines and canceling at the end by e2fsck Test6: mdadm --create --level 5 -n 6 --chunk=512 --assume-clean /dev/md2 /dev/sd{a,b,c,f,e}4 missing - try original superblock - bad superblock or damage partitiontable - lots of checksumm error in group deskriptor - ends with conflict in inode table with another filesystem block -> filesize 542MB with 15727702 lines and cancelingat the end by e2fsck Teset6 looks like the best one, but what do you think and perhaps what could i do else? Any further help? Many thanks Sunny