2002-03-06 07:39:22

by Michael Cheung

[permalink] [raw]
Subject: mount -o remount,ro cause error "device is busy"

hi, all;
I have upgraded my kernel to version 2.4.
And i have tested 2.4.16 and 2.4.18. Both of these
two version have the same problem when system reboot.
"/: device is busy";
in shutdown script:
umount -a
mount -n -o ro,remount /
these two line result error: device is busy.

I switch to init 1, and all user process go away.
except the following:
root 1 0.1 0.7 1056 484 ? S 15:46 0:04 init [S]
root 2 0.0 0.0 0 0 ? SW 15:46 0:00 [keventd]
root 3 0.0 0.0 0 0 ? SWN 15:46 0:00 [ksoftirqd_CPU0]
root 4 0.0 0.0 0 0 ? SW 15:46 0:00 [kswapd]
root 5 0.0 0.0 0 0 ? SW 15:46 0:00 [bdflush]
root 6 0.0 0.0 0 0 ? SW 15:46 0:00 [kupdated]
root 1042 0.0 0.7 1056 484 tty1 S 16:33 0:00 init [S]
root 1043 0.6 1.5 1840 1004 tty1 S 16:33 0:00 /bin/sh
root 1045 0.0 1.0 2260 680 tty1 R 16:33 0:00 ps aux

then i try
mount -o ro,remount /
error occurs: device is busy.

and i try
mount -o ro,remount /usr
(another partition)
also error occurs: device is busy.

but when i try umount /usr,
it works.

certainly, there is error
device is busy for command umount /.

How can i resolve this problem?

Regards;
Michael


2002-03-06 07:48:43

by Mike Fedyk

[permalink] [raw]
Subject: Re: mount -o remount,ro cause error "device is busy"

On Wed, Mar 06, 2002 at 04:40:10PM +0900, Michael Cheung wrote:
> hi, all;
> I have upgraded my kernel to version 2.4.
> And i have tested 2.4.16 and 2.4.18. Both of these
> two version have the same problem when system reboot.
> "/: device is busy";
> in shutdown script:
> umount -a
> mount -n -o ro,remount /
> these two line result error: device is busy.
>

We need more info about your config. Do you have any patches in this
kernel? What modules have been loaded? Highmem? x86? drive controller?
drive? ram size? lspci output, etc...

2002-03-06 08:12:56

by Michael Cheung

[permalink] [raw]
Subject: Re[2]: mount -o remount,ro cause error "device is busy"

I haven't apply any patch on my 2.4.16 kernel.
But when i test 2.4.18, i apply many netfilter patch
in iptables 1.2.5 via patch-o-matics..
like newnat,ip_nat_h323, iplimit and so on.

I attach my config file for 2.4.18 in this mail.

Regards
Michael


On Tue, 5 Mar 2002 23:49:08 -0800
Mike Fedyk <[email protected]> wrote:

> On Wed, Mar 06, 2002 at 04:40:10PM +0900, Michael Cheung wrote:
> > hi, all;
> > I have upgraded my kernel to version 2.4.
> > And i have tested 2.4.16 and 2.4.18. Both of these
> > two version have the same problem when system reboot.
> > "/: device is busy";
> > in shutdown script:
> > umount -a
> > mount -n -o ro,remount /
> > these two line result error: device is busy.
> >
>
> We need more info about your config. Do you have any patches in this
> kernel? What modules have been loaded? Highmem? x86? drive controller?
> drive? ram size? lspci output, etc...
>


Attachments:
20020306.cfg (18.06 kB)

2002-03-06 08:15:47

by Andreas Dilger

[permalink] [raw]
Subject: Re: mount -o remount,ro cause error "device is busy"

On Mar 05, 2002 23:49 -0800, Mike Fedyk wrote:
> On Wed, Mar 06, 2002 at 04:40:10PM +0900, Michael Cheung wrote:
> > I have upgraded my kernel to version 2.4.
> > And i have tested 2.4.16 and 2.4.18. Both of these
> > two version have the same problem when system reboot.
> > "/: device is busy";
> > in shutdown script:
> > umount -a
> > mount -n -o ro,remount /
> > these two line result error: device is busy.
> >
>
> We need more info about your config. Do you have any patches in this
> kernel? What modules have been loaded? Highmem? x86? drive controller?
> drive? ram size? lspci output, etc...

Please don't send that. It clearly appears to be a user problem.
Order of operations, as I read in the original email:
1) "/" and "/usr" are busy
2) shut down to single user mode
3) "/" still busy
4) "/usr" can be unmounted
5) didn't check that root can be remounted after umounting "/usr"

Clearly, some program is keeping "/usr" busy (which is keeping "/" busy)
before the change to single user mode. Just a bit of "lsof" needed to
find such things.

Cheers, Andreas
--
Andreas Dilger
http://sourceforge.net/projects/ext2resize/
http://www-mddsp.enel.ucalgary.ca/People/adilger/

2002-03-06 08:33:09

by Michael Cheung

[permalink] [raw]
Subject: Re[2]: mount -o remount,ro cause error "device is busy"

hi,

maybe i am wrong, but I really can't find any other process runing.

my step is:
1) "/" and "/usr" are busy
2) shut down to single user mode
3) "/" still busy
4) "/usr" can be unmounted, but can't mount -o ro,remount /usr, show busy error.
5) umount -a, after this, only /proc and / exist.
6) mount -o ro,remount /, show busy error.

I have mentioned I have used "ps aux" to check the process list,
there are no user process left. except the following: (repost)
root 1 0.1 0.7 1056 484 ? S 15:46 0:04 init [S]
root 2 0.0 0.0 0 0 ? SW 15:46 0:00 [keventd]
root 3 0.0 0.0 0 0 ? SWN 15:46 0:00 [ksoftirqd_CPU0]
root 4 0.0 0.0 0 0 ? SW 15:46 0:00 [kswapd]
root 5 0.0 0.0 0 0 ? SW 15:46 0:00 [bdflush]
root 6 0.0 0.0 0 0 ? SW 15:46 0:00 [kupdated]
root 1042 0.0 0.7 1056 484 tty1 S 16:33 0:00 init [S]
root 1043 0.6 1.5 1840 1004 tty1 S 16:33 0:00 /bin/sh
root 1045 0.0 1.0 2260 680 tty1 R 16:33 0:00 ps aux

and I also checked by fuser -v /usr,
only used by kernel.
and fuser -c /, show many process list above.

If i have a mistake, would you like to tell me where is the mistake?

thanks.

Regards;
Michael


On Wed, 6 Mar 2002 01:15:19 -0700
Andreas Dilger <[email protected]> wrote:

> On Mar 05, 2002 23:49 -0800, Mike Fedyk wrote:
> > On Wed, Mar 06, 2002 at 04:40:10PM +0900, Michael Cheung wrote:
> > > I have upgraded my kernel to version 2.4.
> > > And i have tested 2.4.16 and 2.4.18. Both of these
> > > two version have the same problem when system reboot.
> > > "/: device is busy";
> > > in shutdown script:
> > > umount -a
> > > mount -n -o ro,remount /
> > > these two line result error: device is busy.
> > >
> >
> > We need more info about your config. Do you have any patches in this
> > kernel? What modules have been loaded? Highmem? x86? drive controller?
> > drive? ram size? lspci output, etc...
>
> Please don't send that. It clearly appears to be a user problem.
> Order of operations, as I read in the original email:
> 1) "/" and "/usr" are busy
> 2) shut down to single user mode
> 3) "/" still busy
> 4) "/usr" can be unmounted
> 5) didn't check that root can be remounted after umounting "/usr"
>
> Clearly, some program is keeping "/usr" busy (which is keeping "/" busy)
> before the change to single user mode. Just a bit of "lsof" needed to
> find such things.
>
> Cheers, Andreas
> --
> Andreas Dilger
> http://sourceforge.net/projects/ext2resize/
> http://www-mddsp.enel.ucalgary.ca/People/adilger/
>
>


2002-03-06 09:47:27

by Andreas Schwab

[permalink] [raw]
Subject: Re: Re[2]: mount -o remount,ro cause error "device is busy"

Michael Cheung <[email protected]> writes:

|> hi,
|>
|> maybe i am wrong, but I really can't find any other process runing.
|>
|> my step is:
|> 1) "/" and "/usr" are busy
|> 2) shut down to single user mode
|> 3) "/" still busy
|> 4) "/usr" can be unmounted, but can't mount -o ro,remount /usr, show busy error.
|> 5) umount -a, after this, only /proc and / exist.
|> 6) mount -o ro,remount /, show busy error.
|>
|> I have mentioned I have used "ps aux" to check the process list,
|> there are no user process left. except the following: (repost)
|> root 1 0.1 0.7 1056 484 ? S 15:46 0:04 init [S]
|> root 2 0.0 0.0 0 0 ? SW 15:46 0:00 [keventd]
|> root 3 0.0 0.0 0 0 ? SWN 15:46 0:00 [ksoftirqd_CPU0]
|> root 4 0.0 0.0 0 0 ? SW 15:46 0:00 [kswapd]
|> root 5 0.0 0.0 0 0 ? SW 15:46 0:00 [bdflush]
|> root 6 0.0 0.0 0 0 ? SW 15:46 0:00 [kupdated]
|> root 1042 0.0 0.7 1056 484 tty1 S 16:33 0:00 init [S]
|> root 1043 0.6 1.5 1840 1004 tty1 S 16:33 0:00 /bin/sh
|> root 1045 0.0 1.0 2260 680 tty1 R 16:33 0:00 ps aux
|>
|> and I also checked by fuser -v /usr,
|> only used by kernel.
|> and fuser -c /, show many process list above.
|>
|> If i have a mistake, would you like to tell me where is the mistake?

Check for references to deleted files (/proc/*/fd). "init u" should help.

Andreas.

--
Andreas Schwab, SuSE Labs, [email protected]
SuSE GmbH, Deutschherrnstr. 15-19, D-90429 N?rnberg
Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5
"And now for something completely different."

2002-03-07 02:28:23

by Petro

[permalink] [raw]
Subject: Re: mount -o remount,ro cause error "device is busy"

On Wed, Mar 06, 2002 at 05:33:45PM +0900, Michael Cheung wrote:
> hi,
>
> maybe i am wrong, but I really can't find any other process runing.
>
> my step is:
> 1) "/" and "/usr" are busy
> 2) shut down to single user mode
> 3) "/" still busy
> 4) "/usr" can be unmounted, but can't mount -o ro,remount /usr, show busy error.
> 5) umount -a, after this, only /proc and / exist.
> 6) mount -o ro,remount /, show busy error.
> On Wed, 6 Mar 2002 01:15:19 -0700
> Andreas Dilger <[email protected]> wrote:
> > Clearly, some program is keeping "/usr" busy (which is keeping "/" busy)
> > before the change to single user mode. Just a bit of "lsof" needed to
> > find such things. ||||
^^^^
Best bet is to man lsof.

lsof's your buddy.

--
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