Re: [Fwd: Re: mdadm: spare rebuilding]

[Jon Buckingham <jbuckingham@xxxxxxxxxxxxxxxx>]

Hi Neil

So, a little while ago I did upgrade the kernel
(2.6.22.18-0.2-default), but it did not seem to make any difference to the
'echo sync > /sys/block/md3/md/sync_action'.

After receiving your latest email, I did the following...

echo sync > /sys/block/md3/md/sync_action
(device busy reported to konsole as before)
echo idle > /sys/block/md3/md/sync_action
echo sync > /sys/block/md3/md/sync_action
(device busy reported to konsole as before)

Then checked "top" - and saw significant activity from
md3_sync and md3_raid5 processes.
Also cat /proc/mdstat showed that a resync was actively happening,
and sure enough, after a couple of hours I now have
4 active devices in the array!

So I suspect a combination of the new kernel and the "idle"
sorted the problem, whatever it was.

Thanks!
And thanks for writing mdadm and for your support.

Jon B

NeilBrown wrote:
> On Wed, July 2, 2008 4:37 am, Jon Buckingham wrote:
> > Hi Neil - any thoughts on how I can debug/fix this?
>
> Sorry for the slow responses - I seem to have been very busy lately.
>
> No, unmount isn't needed.
> I cannot really imagine what is happening.
> Maybe write "idle" to the sync_action file first, then try
> "sync", but that seems unlikely.
>
> Maybe unmount, stop the array,
>    echo 0 > /sys/modules/md-mod/paramters/start_ro
> and assemble that array again
>    mdadm -A /dev/md3 /dev/sd[abcd]4
> and see if that helps.
>
> Maybe try a newer kernel if that is an option.
>
> NeilBrown
>
> > Thanks
> >
> > Jon B
> >
> > -------- Original Message --------
> > Subject: Re: mdadm: spare rebuilding
> > Date: Sat, 28 Jun 2008 20:42:56 +0100
> > From: Jon Buckingham <jbuckingham@xxxxxxxxxxxxxxxx>
> > Reply-To: jbuckingham@xxxxxxxxxxxxxxxx
> > To: Neil Brown <neilb@xxxxxxx>
> > CC: linux-raid@xxxxxxxxxxxxxxx
> > References: <48615EE7.7000502@xxxxxxxxxxxxxxxx>
> > <18532.47293.808234.949005@xxxxxxxxxxxxxx>
> >
> > Neil Brown wrote:
> > > Maybe a bug that has since been fixed.
> > > What happens if you
> > >   echo sync > /sys/block/md3/md/sync_action
> > > ??
> > nas:~ # echo sync > /sys/block/md3/md/sync_action
> > -bash: echo: write error: Device or resource busy
> >
> > Should I unmount first?
> > Any other info?
> >
> > Thanks
> >
> > Jon B

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