From mboxrd@z Thu Jan  1 00:00:00 1970
From: "bo" <bo@sosnetwork.net>
Subject: Couldn't umount on /mnt/md0-device busy???
Date: Wed, 17 Jul 2002 10:35:28 -0700
Sender: linux-raid-owner@vger.kernel.org
Message-ID: <003c01c22db8$57b86590$5701a8c0@bomoon>
References: <Pine.LNX.4.33.0207161515560.29547-100000@pandora.is.bizsystems.com> <15668.41627.988382.451061@notabene.cse.unsw.edu.au>
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Hello!

I have found a VERY strange issue on using the name "md0" as a mount point.
If I use "/mnt/md0" as a mount point for the md device or normal HD device,
I could not umount it after booting the system having "device is busy"
error.

However, it is OK if I manually make a RAID then mount it to "/mnt/md0".
I checked if it has any processes running on it with "fuser" but nothing.

Does "/mnt/md0" have a special meaning(usage) for system?

Please provide me a clue.

Thanks,

//Bo

The followins are my experiment on this issue;

root@P3000-PP1:/home/bmoon# cat /proc/mounts
/dev/root / ext2 rw 0 0
none /proc proc rw 0 0
/dev/md0 /mnt/md0 ext2 rw 0 0
/dev/md3 /mnt/md3 ext2 rw 0 0

root@P3000-PP1:/home/bmoon# umount /mnt/md0
umount: /mnt/md0: device is busy
---------------
root@P3000-PP1:/etc# fuser -v /mnt/md0

                     USER        PID ACCESS COMMAND
/mnt/md0            root     kernel mount  /mnt/md0

----------------after chnage the name of mount point  from /mnt/md0 to
/mnt/user---------------
root@P3000-PP1:/home/bmoon# cat /proc/mounts
/dev/root / ext2 rw 0 0
none /proc proc rw 0 0
/dev/md0 /mnt/user ext2 rw 0 0
/dev/md3 /mnt/md3 ext2 rw 0 0

root@P3000-PP1:/home/bmoon# umount /mnt/user
root@P3000-PP1:/home/bmoon#
------------------------
root@P3000-PP1:/etc# vi fstab
/dev/hda2        /               ext2    defaults        1 1
none             /proc           proc    defaults        0 0
/dev/hda3        swap            swap    defaults        0 0
/dev/md0         /mnt/user       ext2    defaults        0 0
/dev/md3         /mnt/md3        ext2    defaults        0 0

Another experiment
----------------------
root@P3000-PP1:/home/bmoon# cat /proc/mounts
/dev/root / ext2 rw 0 0
none /proc proc rw 0 0
/dev/hdb2  /mnt/md0 ext2 rw 0 0
/dev/md3 /mnt/md3 ext2 rw 0 0

root@P3000-PP1:/home/bmoon# umount /mnt/md0
umount:  /mnt/md0:  device is busy