Re: [PATCH] mdadm: fix reshape from RAID5 to RAID6 with backup file

[Jes Sorensen <jes@trained-monkey.org>]

On 3/26/21 7:59 AM, Nigel Croxon wrote:> ----- Original Message ----->
From: "Oleksandr Shchirskyi" <oleksandr.shchirskyi@linux.intel.com>> To:
"Nigel Croxon" <ncroxon@redhat.com>
> Cc: linux-raid@vger.kernel.org, "Mariusz Tkaczyk" <mariusz.tkaczyk@linux.intel.com>, "Jes Sorensen" <jes@trained-monkey.org>
> Sent: Tuesday, March 23, 2021 4:58:27 PM
> Subject: Re: [PATCH] mdadm: fix reshape from RAID5 to RAID6 with backup file
> 
> On 3/23/2021 5:36 PM, Nigel Croxon wrote:
>> Oleksandr,
>> Can you post your dmesg output when running the commands?
>>
>> I've back down from 5.11 to 5.8 and I still see:
>> [  +0.042694] md/raid0:md126: raid5 must have missing parity disk!
>> [  +0.000001] md: md126: raid0 would not accept array
>>
>> Thanks, Nigel
> 
> Hello Nigel,
> 
> I've switched to 4.18.0-240.el8.x86_64 kernel (I have RHEL8.3) and I still 
> have the same results, issue is still easily reproducible when patch 
> 4ae96c8 is applied.
> 
> Cropped test logs with and w/o your patch:
> 
> # git log -n1 --oneline
> f94df5c (HEAD -> master, origin/master, origin/HEAD) imsm: support for 
> third Sata controller
> # make clean; make; make install-systemd; make install
> # mdadm -CR imsm0 -e imsm -n4 /dev/nvme[0-3]n1 && mdadm -CR volume -l0 
> --chunk 64 --size=10G --raid-devices=1 /dev/nvme0n1 --force
> # mdadm -G /dev/md/imsm0 -n2
> # dmesg -c
> [  393.530389] md126: detected capacity change from 0 to 10737418240
> [  407.139318] md/raid:md126: device nvme0n1 operational as raid disk 0
> [  407.153920] md/raid:md126: raid level 4 active with 1 out of 2 devices, 
> algorithm 5
> [  407.246037] md: reshape of RAID array md126
> [  407.357940] md: md126: reshape interrupted.
> [  407.388144] md: reshape of RAID array md126
> [  407.398737] md: md126: reshape interrupted.
> [  407.403486] md: reshape of RAID array md126
> [  459.414250] md: md126: reshape done.
> # cat /proc/mdstat
> Personalities : [raid0] [raid6] [raid5] [raid4]
> md126 : active raid4 nvme3n1[2] nvme0n1[0]
>        10485760 blocks super external:/md127/0 level 4, 64k chunk, 
> algorithm 0 [3/2] [UU_]
> 
> md127 : inactive nvme3n1[3](S) nvme2n1[2](S) nvme1n1[1](S) nvme0n1[0](S)
>        4420 blocks super external:imsm
> 
> unused devices: <none>
> 
> # mdadm -Ss; wipefs -a /dev/nvme[0-3]n1
> # dmesg -C
> # git revert 4ae96c802203ec3cfbb089240c56d61f7f4661b3
> # make clean; make; make install-systemd; make install
> # mdadm -CR imsm0 -e imsm -n4 /dev/nvme[0-3]n1 && mdadm -CR volume -l0 
> --chunk 64 --size=10G --raid-devices=1 /dev/nvme0n1 --force
> # mdadm -G /dev/md/imsm0 -n2
> # dmesg -c
> [  623.772039] md126: detected capacity change from 0 to 10737418240
> [  644.823245] md/raid:md126: device nvme0n1 operational as raid disk 0
> [  644.838542] md/raid:md126: raid level 4 active with 1 out of 2 devices, 
> algorithm 5
> [  644.928672] md: reshape of RAID array md126
> [  697.405351] md: md126: reshape done.
> [  697.409659] md126: detected capacity change from 10737418240 to 21474836480
> # cat /proc/mdstat
> Personalities : [raid0] [raid6] [raid5] [raid4]
> md126 : active raid0 nvme3n1[2] nvme0n1[0]
>        20971520 blocks super external:/md127/0 64k chunks
> 
> md127 : inactive nvme3n1[3](S) nvme2n1[2](S) nvme1n1[1](S) nvme0n1[0](S)
>        4420 blocks super external:imsm
> 
> 
> Do you need more detailed logs? My system/drives configuration details?
> 
> Regards,
> Oleksandr Shchirskyi
> 
> 
> 
> 
> From f0c80c8e90b2ce113b6e22f919659430d3d20efa Mon Sep 17 00:00:00 2001
> From: Nigel Croxon <ncroxon@redhat.com>
> Date: Fri, 26 Mar 2021 07:56:10 -0400
> Subject: [PATCH] mdadm: fix growing containers
> 
> This fixes growing containers which was broken with
> commit 4ae96c802203ec3c (mdadm: fix reshape from RAID5 to RAID6 with
> backup file)
> 
> The issue being that containers use the function
> wait_for_reshape_isms and expect a number value and not a
> string value of "max".  The change is to test for external
> before setting the correct value.
> 
> Signed-off-by: Nigel Croxon <ncroxon@redhat.com>

I was about to revert the problematic patch. Oleksandr, can you confirm
if it resolves the issues you were seeing?

Thanks,
Jes