On Tue, Dec 15, 2020 at 10:40 AM Sébastien Luttringer <seblu@xxxxxxxxx> wrote:
>
> Hello,
>
> After a clean reboot to the new kernel 5.10.0 my 40TB md raid5 array size
> droped to 7TB.
> The previous kernel was 5.9.5. Rebooting back to the 5.9.5 didn't fix the
> issue.
>
> # cat /proc/mdstat
> Personalities : [raid6] [raid5] [raid4]
> md0 : active raid5 sdf[9] sdd[10] sda[7] sdb[6] sdc[11] sde[8]
> 6857871360 blocks super 1.2 level 5, 512k chunk, algorithm 2 [6/6]
> [UUUUUU]
>
> unused devices: <none>
>
>
> journalctl -oshort-iso --no-hostname -b -6|grep md0
> 2020-12-04T02:30:47+0100 kernel: md/raid:md0: device sdf operational as raid
> disk 0
> 2020-12-04T02:30:47+0100 kernel: md/raid:md0: device sda operational as raid
> disk 5
> 2020-12-04T02:30:47+0100 kernel: md/raid:md0: device sdd operational as raid
> disk 4
> 2020-12-04T02:30:47+0100 kernel: md/raid:md0: device sde operational as raid
> disk 2
> 2020-12-04T02:30:47+0100 kernel: md/raid:md0: device sdc operational as raid
> disk 1
> 2020-12-04T02:30:47+0100 kernel: md/raid:md0: device sdb operational as raid
> disk 3
> 2020-12-04T02:30:47+0100 kernel: md/raid:md0: raid level 5 active with 6 out of
> 6 devices, algorithm 2
> 2020-12-04T02:30:47+0100 kernel: md0: detected capacity change from 0 to
> 40007809105920
> 2020-12-04T02:31:47+0100 kernel: EXT4-fs (md0): mounted filesystem with ordered
> data mode. Opts: (null)
>
> # journalctl -oshort-iso --no-hostname -b -5|grep md0
> 2020-12-15T03:53:00+0100 kernel: md/raid:md0: device sdf operational as raid
> disk 0
> 2020-12-15T03:53:00+0100 kernel: md/raid:md0: device sda operational as raid
> disk 5
> 2020-12-15T03:53:00+0100 kernel: md/raid:md0: device sde operational as raid
> disk 2
> 2020-12-15T03:53:00+0100 kernel: md/raid:md0: device sdd operational as raid
> disk 4
> 2020-12-15T03:53:00+0100 kernel: md/raid:md0: device sdc operational as raid
> disk 1
> 2020-12-15T03:53:00+0100 kernel: md/raid:md0: device sdb operational as raid
> disk 3
> 2020-12-15T03:53:00+0100 kernel: md/raid:md0: raid level 5 active with 6 out of
> 6 devices, algorithm 2
> 2020-12-15T03:53:00+0100 kernel: md0: detected capacity change from 0 to
> 7022460272640
> 2020-12-15T03:54:20+0100 systemd-fsck[1009]: fsck.ext4: Invalid argument while
> trying to open /dev/md0
>
> There is no log of hardware errors or unclean unmounting.
>
> # mdadm -D /dev/md0
> /dev/md0:
> Version : 1.2
> Creation Time : Mon Jan 24 02:53:21 2011
> Raid Level : raid5
> Array Size : 6857871360 (6540.18 GiB 7022.46 GB)
> Used Dev Size : 1371574272 (1308.04 GiB 1404.49 GB)
> Raid Devices : 6
> Total Devices : 6
> Persistence : Superblock is persistent
>
> Update Time : Tue Dec 15 17:53:13 2020
> State : clean
> Active Devices : 6
> Working Devices : 6
> Failed Devices : 0
> Spare Devices : 0
>
> Layout : left-symmetric
> Chunk Size : 512K
>
> Consistency Policy : resync
>
> Name : white:0 (local to host white)
> UUID : affd87df:da503e3b:52a8b97f:77b80c0c
> Events : 1791763
>
> Number Major Minor RaidDevice State
> 9 8 80 0 active sync /dev/sdf
> 11 8 32 1 active sync /dev/sdc
> 8 8 64 2 active sync /dev/sde
> 6 8 16 3 active sync /dev/sdb
> 10 8 48 4 active sync /dev/sdd
> 7 8 0 5 active sync /dev/sda
>
> The mdadm userspace as not been updated.
> # mdadm -V
> mdadm - v4.1 - 2018-10-01
>
> An `mdadm --action check /dev/md0` was run without errors.
>
> 1) What's the best option to restore the size without loosing the data?
> 2) Is this issue can be related to the kernel upgrade or it's fortuitous?
Hi,
I am very sorry for this problem. This is a bug in 5.10 which is fixed
in 5.10.1.
To fix it, please upgrade your kernel to 5.10.1 (or downgrade to previous
version). In many cases, the array should be back normal. If not, please try
mdadm --grow --size <size> /dev/mdXXX.
If the original array uses the full disk/partition, you can use "max" for <size>
to safe some calculation.
Please let me know if you have future problem with it.
Thanks,
Song
