[Fwd: serious data corruption when doing "mount -o remount,ro /"]

[Fwd: serious data corruption when doing "mount -o remount,ro /"]

[Michael Weissenbacher]

Sorry, i should have mentioned, i got the same problem with all of these 
kernel versions:
2.6.9-rc1-mm4
2.6.8.1-ck6
2.6.8-gentoo-r3 patched with reiser4

-------- Original Message --------
Subject: serious data corruption when doing "mount -o remount,ro /"
Date: Mon, 13 Sep 2004 13:16:37 +0200
From: Michael Weissenbacher <webmaster@dermichi.com>
To: ReiserFS List <reiserfs-list@namesys.com>

After running reiser4 as / filesystem for some time i got a serious
problem yesterday. In short: the FS didn't survive a "mount -o
remount,ro /". Here is what I did:
# init 1
# mount -o remount,ro /
# fsck.reiser4 /dev/hda7
fsck complained about not finding the root directory and said that the
tree height of 4 was incorrect because it should be 255. I thought this
would be a temporary problem as i had worked with my system until 30
seconds before without a problem. So i rebooted, which was really not a
good idea. The FS was unmountable after that. After running fsck from a
livecd to repair the FS, which took about 2 hours, the FS was restored
almost completely, but then i went back to a backup to be safe.
I am still able to reproduce random corruption by doing a remount ro. I
also get this problem if i use the "magic sysreq key" to do the remount.
If i remount the FS rw again and shutdown after that the FS does NOT get
corrupted at all.
I am not posting details about my system since i was able to get the
same corruption on two completely different systems. Also i'm not
including fsck output as the corruption is random and reports different
things every time.
Any ideas what could be causing this?

Michael

reiser4: serious data corruption when doing "mount -o remount,ro /"

[Michael Weissenbacher]

I just read in 2004.03.26/READ.ME that remount is not supported yet. But 
this does not apply to the current version, does it?

Michael Weissenbacher wrote:
> Sorry, i should have mentioned, i got the same problem with all of these 
> kernel versions:
> 2.6.9-rc1-mm4
> 2.6.8.1-ck6
> 2.6.8-gentoo-r3 patched with reiser4
> 
> -------- Original Message --------
> Subject: serious data corruption when doing "mount -o remount,ro /"
> Date: Mon, 13 Sep 2004 13:16:37 +0200
> From: Michael Weissenbacher <webmaster@dermichi.com>
> To: ReiserFS List <reiserfs-list@namesys.com>
> 
> After running reiser4 as / filesystem for some time i got a serious
> problem yesterday. In short: the FS didn't survive a "mount -o
> remount,ro /". Here is what I did:
> # init 1
> # mount -o remount,ro /
> # fsck.reiser4 /dev/hda7
> fsck complained about not finding the root directory and said that the
> tree height of 4 was incorrect because it should be 255. I thought this
> would be a temporary problem as i had worked with my system until 30
> seconds before without a problem. So i rebooted, which was really not a
> good idea. The FS was unmountable after that. After running fsck from a
> livecd to repair the FS, which took about 2 hours, the FS was restored
> almost completely, but then i went back to a backup to be safe.
> I am still able to reproduce random corruption by doing a remount ro. I
> also get this problem if i use the "magic sysreq key" to do the remount.
> If i remount the FS rw again and shutdown after that the FS does NOT get
> corrupted at all.
> I am not posting details about my system since i was able to get the
> same corruption on two completely different systems. Also i'm not
> including fsck output as the corruption is random and reports different
> things every time.
> Any ideas what could be causing this?
> 
> Michael
>