From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bart Kus Subject: Used Dev Size is wrong Date: Sun, 25 Oct 2009 09:56:15 -0700 Message-ID: <4AE4832F.7010602@bartk.us> 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 Hello RAID gurus, I recently upgraded my MD 10x1TB RAID6 to a 10x2TB RAID6. I did this by replacing all the 1TB drives in the array with 2TB drives, no more than 2 at a time, and letting the array rebuild to assimilate the fresh drive(s). The array finished its last rebuild and showed an Array Size of 8000GB, and a Used Dev Size of 2000GB. Since this isn't the 16TB I was looking for, I went through a grow operation: # mdadm /dev/md4 -G -z max This started a resync @ 50% complete and continued from there. This had the expected effect of increasing the reported Array Size to 16000GB, but it also unexpectedly increased the Used Dev Size to 4000GB! I'm worried this incorrect size will lead to errors down the road. What can I do to correct this? Here are the details of the case: jo dev # cat /proc/mdstat Personalities : [raid1] [raid6] [raid5] [raid4] md4 : active raid6 sdl1[13] sdj1[19] sdg1[18] sdd1[17] sdf1[16] sdc1[15] sdi1[14] sde1[12] sdk1[11] sdh1[10] 15628094464 blocks super 1.2 level 6, 64k chunk, algorithm 2 [10/10] [UUUUUUUUUU] [===========>.........] resync = 55.6% (1087519792/1953511808) finish=342.1min speed=42184K/sec # mdadm --detail /dev/md4 /dev/md4: Version : 1.02 Creation Time : Sun Aug 10 23:41:49 2008 Raid Level : raid6 Array Size : 15628094464 (14904.11 GiB 16003.17 GB) Used Dev Size : 3907023616 (3726.03 GiB 4000.79 GB) Raid Devices : 10 Total Devices : 10 Preferred Minor : 4 Persistence : Superblock is persistent Update Time : Sun Oct 25 09:07:29 2009 State : active, resyncing Active Devices : 10 Working Devices : 10 Failed Devices : 0 Spare Devices : 0 Chunk Size : 64K Rebuild Status : 55% complete Name : 4 UUID : da14eb85:00658f24:80f7a070:b9026515 Events : 2901293 Number Major Minor RaidDevice State 15 8 33 0 active sync /dev/sdc1 14 8 129 1 active sync /dev/sdi1 12 8 65 2 active sync /dev/sde1 16 8 81 3 active sync /dev/sdf1 17 8 49 4 active sync /dev/sdd1 18 8 97 5 active sync /dev/sdg1 10 8 113 6 active sync /dev/sdh1 19 8 145 7 active sync /dev/sdj1 11 8 161 8 active sync /dev/sdk1 13 8 177 9 active sync /dev/sdl1 # uname -a Linux jo.bartk.us 2.6.29-gentoo-r5 #1 SMP Fri Jun 19 23:04:52 PDT 2009 x86_64 Intel(R) Pentium(R) D CPU 2.80GHz GenuineIntel GNU/Linux # mdadm --examine /dev/sdc1 /dev/sdc1: Magic : a92b4efc Version : 1.2 Feature Map : 0x0 Array UUID : da14eb85:00658f24:80f7a070:b9026515 Name : 4 Creation Time : Sun Aug 10 23:41:49 2008 Raid Level : raid6 Raid Devices : 10 Avail Dev Size : 3907023730 (1863.01 GiB 2000.40 GB) Array Size : 31256188928 (14904.11 GiB 16003.17 GB) Used Dev Size : 3907023616 (1863.01 GiB 2000.40 GB) Data Offset : 272 sectors Super Offset : 8 sectors State : active Device UUID : 56d9fdeb:5170f643:5d4c4a2b:b656838a Update Time : Sun Oct 25 09:07:29 2009 Checksum : c8785262 - correct Events : 2901293 Chunk Size : 64K Array Slot : 15 (failed, failed, failed, failed, failed, failed, failed, failed, failed, failed, 6, 8, 2, 9, 1, 0, 3, 4, 5, 7) Array State : Uuuuuuuuuu 10 failed # fdisk /dev/sdc The number of cylinders for this disk is set to 243201. There is nothing wrong with that, but this is larger than 1024, and could in certain setups cause problems with: 1) software that runs at boot time (e.g., old versions of LILO) 2) booting and partitioning software from other OSs (e.g., DOS FDISK, OS/2 FDISK) Command (m for help): p Disk /dev/sdc: 2000.3 GB, 2000398934016 bytes 255 heads, 63 sectors/track, 243201 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Disk identifier: 0x3a18d025 Device Boot Start End Blocks Id System /dev/sdc1 1 243201 1953512001 fd Linux raid autodetect Thanks in advance for your help! --Bart