Thanks, can i just double check the command with you mdadm --create /dev/md0 --chunk=512 --metadata=1.0 --assume-clean --level=5 --raid-devices=4 /dev/sde /dev/sdc /dev/sdd /dev/sdb On 12 October 2011 05:10, NeilBrown <neilb@xxxxxxx> wrote: > On Mon, 10 Oct 2011 22:47:58 +0100 Michael Busby <michael.a.busby@xxxxxxxxx> > wrote: > >> I have a quick question i remember reading somewhere about not using >> metadata version 0.9 with drives larger than 2tb, >> > at the moment i have the following >> > >> > root@BlueBolt:~# cat /proc/mdstat >> > Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] >> > md0 : active raid5 sdd[2] sde[0] sdb[3] sdc[1] >> > 5860543488 blocks level 5, 512k chunk, algorithm 2 [4/4] [UUUU] >> > bitmap: 2/15 pages [8KB], 65536KB chunk >> > unused devices: <none> >> > root@BlueBolt:~# mdadm --detail /dev/md0 >> > /dev/md0: >> > Version : 0.90 >> > Creation Time : Mon Jul 4 15:08:38 2011 >> > Raid Level : raid5 >> > Array Size : 5860543488 (5589.05 GiB 6001.20 GB) >> > Used Dev Size : 1953514496 (1863.02 GiB 2000.40 GB) >> > Raid Devices : 4 >> > Total Devices : 4 >> > Preferred Minor : 0 >> > Persistence : Superblock is persistent >> > Intent Bitmap : Internal >> > Update Time : Mon Oct 10 22:44:11 2011 >> > State : active >> > Active Devices : 4 >> > Working Devices : 4 >> > Failed Devices : 0 >> > Spare Devices : 0 >> > Layout : left-symmetric >> > Chunk Size : 512K >> > UUID : ddab6c38:dee3ead0:95ba4558:1c9a49ed (local to host BlueBolt) >> > Events : 0.2836102 >> > Number Major Minor RaidDevice State >> > 0 8 64 0 active sync /dev/sde >> > 1 8 32 1 active sync /dev/sdc >> > 2 8 48 2 active sync /dev/sdd >> > 3 8 16 3 active sync /dev/sdb >> > which as you can see if using 0.90, i am looking at replacing all the 2tb drives with 3tb versions, would i need to update the metadata version? if so how can i go about this? > > With a really recent kernel (3.1) and recent mdadm (also not released yet), > 0.90 can go up to 4TB (it has 32 bits to count kilobytes with). > > Alternately you need to convert to 1.0 metadata. > > Currently the only way to do this is to 'create' the array again. > Be sure to specified the same chunk size, the right metadata, the name level > and number of disks, and the correct disks in the correct order. > An use "--assume-clean". Then check your data is still consistent. > With --assume-clean and a read-only mount, no data will actually be changed, > only metadata. > > NeilBrown > > -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
