Array will not resync.

Array will not resync.

[simd]

Hello,

I cannot get my RAID 6 array to resync.

I'm using mdadm version v4.1. I've tried kernels 5.18.X, 6.0.X, and
6.3.X on Devuan (Debian) Linux.

% echo resync > /sys/devices/virtual/block/md127/md/sync_action

Does nothing. 

% mdadm --assemble --update=resync /dev/md127

Does nothing.

I should see a status change to resync with mdadm --detail /dev/md127 and
hear some activity from the drives.

I tried adding the verbose option, but it only lists the recognizing of
the drives and adding them to the array.

The array currently has some mismatches which need to be corrected. It's
currently registering all devices in "active sync" status and says that
it is "clean".

I tried setting the flag, in misc mode, to readonly and then back to
readwrite but that still doesn't allow the array to be resync'd.

In desperation, I tried unplugging one of the drives, it holds most/all
of the mismatches -- the SATA cable was going bad, and then I touch(1)ed a
file on the FS and unmounted the FS. Although the array recognized the
failure of the drive, it did not start resync the array upon adding the
drive back into the array.




Any ideas how to resync the array?

Thanks,
David

Re: Array will not resync.

[Yu Kuai]

Hi,

在 2024/02/19 0:23, simd@vfemail.net 写道:
> Hello,
> 
> I cannot get my RAID 6 array to resync.
> 
> I'm using mdadm version v4.1. I've tried kernels 5.18.X, 6.0.X, and
> 6.3.X on Devuan (Debian) Linux.
> 
> % echo resync > /sys/devices/virtual/block/md127/md/sync_action
> 
> Does nothing.
> 
> % mdadm --assemble --update=resync /dev/md127
> 
> Does nothing.

Please note that resync is one-time after assemble the array the first
time, you can't resync again after the array is clean.

> 
> I should see a status change to resync with mdadm --detail /dev/md127 and
> hear some activity from the drives.
> 
> I tried adding the verbose option, but it only lists the recognizing of
> the drives and adding them to the array.
> 
> The array currently has some mismatches which need to be corrected. It's
> currently registering all devices in "active sync" status and says that
> it is "clean".

What you want is "echo check > sync_action", then "cat mismatch_cnt", if
there are really mismatches, "echo repair > sync_action" to fix it.

Thanks,
Kuai

> 
> I tried setting the flag, in misc mode, to readonly and then back to
> readwrite but that still doesn't allow the array to be resync'd.
> 
> In desperation, I tried unplugging one of the drives, it holds most/all
> of the mismatches -- the SATA cable was going bad, and then I touch(1)ed a
> file on the FS and unmounted the FS. Although the array recognized the
> failure of the drive, it did not start resync the array upon adding the
> drive back into the array.
> 
> 
> 
> 
> Any ideas how to resync the array?
> 
> Thanks,
> David
> 
> .
> 

Re: Array will not resync.

[David Niklas]

Ah! I needed to issue repair to the sync_action. Thanks!
mdstat looks normal.

David


On Sun, 18 Feb 2024 19:47:19 -0800
"C.J. Collier" <cjac@colliertech.org> wrote:
> Does the content of /proc/mdstat look interesting to you?
> 
> On Sun, Feb 18, 2024, 17:13 Yu Kuai <yukuai1@huaweicloud.com> wrote:
> 
> > Hi,
> >
> > 在 2024/02/19 0:23, simd@vfemail.net 写道:  
> > > Hello,
> > >
> > > I cannot get my RAID 6 array to resync.
> > >
> > > I'm using mdadm version v4.1. I've tried kernels 5.18.X, 6.0.X, and
> > > 6.3.X on Devuan (Debian) Linux.
> > >
> > > % echo resync > /sys/devices/virtual/block/md127/md/sync_action
> > >
> > > Does nothing.
> > >
> > > % mdadm --assemble --update=resync /dev/md127
> > >
> > > Does nothing.  
> >
> > Please note that resync is one-time after assemble the array the first
> > time, you can't resync again after the array is clean.
> >  
> > >
> > > I should see a status change to resync with mdadm
> > > --detail /dev/md127 and hear some activity from the drives.
> > >
> > > I tried adding the verbose option, but it only lists the
> > > recognizing of the drives and adding them to the array.
> > >
> > > The array currently has some mismatches which need to be corrected.
> > > It's currently registering all devices in "active sync" status and
> > > says that it is "clean".  
> >
> > What you want is "echo check > sync_action", then "cat mismatch_cnt",
> > if there are really mismatches, "echo repair > sync_action" to fix it.
> >
> > Thanks,
> > Kuai
> >  
> > >
> > > I tried setting the flag, in misc mode, to readonly and then back to
> > > readwrite but that still doesn't allow the array to be resync'd.
> > >
> > > In desperation, I tried unplugging one of the drives, it holds
> > > most/all of the mismatches -- the SATA cable was going bad, and
> > > then I touch(1)ed  
> > a  
> > > file on the FS and unmounted the FS. Although the array recognized
> > > the failure of the drive, it did not start resync the array upon
> > > adding the drive back into the array.
> > >
> > >
> > >
> > >
> > > Any ideas how to resync the array?
> > >
> > > Thanks,
> > > David
> > >
> > > .
> > >  
> >
> >
> >