not resyncing after power cut.

not resyncing after power cut.

[Chris Fanning]

Hi,

I've got a couple of doubts.

Since more than a year ago I setup mdadm raid1 on new instalations
(thanks for your work).
On the older machines, mdadm -D shows them in a dirty state. I know
that this is/was as expected. If there is a power cut, the machine
boots and a dirty array is resynced, ¿right?

On newer installations, mdadm -D shows arrays in a clean state. I had
always thought that this was ok becuase I'd read somewhere that the
term 'dirty' was causing confusion and it got changed.
So, state: clean, is what I should expect?

Last week we had a power cut and when the machines booted all arrays
where brought up.
I'm running debian etch and got
INITRDSTART='all'
AUTOSTART="all"
Soon after one of the machines booted, I got users calling me saying
that documents were disappearing ar becoming corrupted. I looked at
cat /proc/mdstat and saw that nothing was being resynced.
I stopped the array, then removed and added one of the partitions to
resync it (could I have done the same using
/usr/share/mdadm/checkarray ?)
Then I ran fsck.ext3 on it (the /dev/md1) . it came back clean. so I
ran fsck.ext3 -f and got lots of errors. Anyway, things are back to
normal now.

So today I installed etch on a new box to try and learn more about this.
To test, I start copying onto the mdadm device and then hit the reset
button on the pc.
On boot, everything starts as normal. no resync, nothing.

Can someone shed some light on this for me please?
Does it have something to do with initramfs?

Thanks.
Chris.
-
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: not resyncing after power cut.

[thunder7]

From: Chris Fanning <christopher.fanning@gmail.com>
Date: Mon, May 21, 2007 at 05:08:47PM +0200
> Hi,
> 
> I've got a couple of doubts.
> 
> Since more than a year ago I setup mdadm raid1 on new instalations
> (thanks for your work).
> On the older machines, mdadm -D shows them in a dirty state. I know
> that this is/was as expected. If there is a power cut, the machine
> boots and a dirty array is resynced, ¿right?
> 
> On newer installations, mdadm -D shows arrays in a clean state. I had
> always thought that this was ok becuase I'd read somewhere that the
> term 'dirty' was causing confusion and it got changed.
> So, state: clean, is what I should expect?
> 
If the newer machines have bitmaps on, the resync is generally faster
than finishing booting - so when you can log in, the array is clean
again.

Do they use bitmaps?

Kind regards,
Jurriaan
-- 
Look - either dualism sucks, or it doesn't.
Debian (Unstable) GNU/Linux 2.6.21-mm2 2x4021 bogomips load load 3.73
the Jack Vance Integral Edition: http://www.integralarchive.org
-
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: not resyncing after power cut.

[Neil Brown]

On Monday May 21, christopher.fanning@gmail.com wrote:
> 
> Can someone shed some light on this for me please?

Sounds like it could be a kernel bug.  What version (exactly) are you
running?

NeilBrown

Re: not resyncing after power cut.

[Chris Fanning]

Hi,

> > Can someone shed some light on this for me please?
>
> Sounds like it could be a kernel bug.  What version (exactly) are you
> running?
>

On the test machine I installed yesterday I'm running a stock debian
etch. 2.6.18-4-686. I didn't do anything tricky during the
installation but just simply followed the installation interface
steps.

The machine that gave me the problems is a 2.6.16 686 booting from xen-3.0.2-2
I also have a second 2.6.16 booting from xen-3.0.2-2.
All machines are debian etch.

I've done this on both the 2.6.16 and the 2.6.18.4
Start copying onto the mdadm device and then hit the reset button on the pc.
On boot, everything starts as normal. no resync, nothing.
Both of them.
The 2.6.16 is compiled by me, but the 2.6.18-4 is etch out of the box.

When I shutdown these machines gracefully, I also get
Stopping array md1 (failed, busy)
....
on the arrays that initramfs setup (I think).

Thanks.
Chris.

> NeilBrown
>