How to remove mounted locations that have been added using the mount command?
You have several directories that are mounted over other directories (the second mount on /mnt/arcserver shadows the first one and so on, and the mounts on /mnt shadow the prior mounts on /mnt/arcserver). This is confusing both for humans and to the umount command. Unmount them from the bottom up:
umount //10.49.4.20/Released
umount //10.49.4.20/released
umount //10.49.4.20/released
umount //metro/released
umount //metro/released
umount //metro/released
If even that fails because umount is tripping on the multiple identical mounts, in desperation, unmount all cifs mounts:
umount -a -t cifs
On Linux, you can unconfuse the situation by moving mounts so that each has its unique, non-overlapping mount point.
mkdir /TMPMNT/{Released,released{1,2},arcserver{1,2,3,4}}
mount --move //10.49.4.20/Released /TMPMNT/Released
mount --move //10.49.4.20/released /TMPMNT/released1
mount --move //10.49.4.20/released /TMPMNT/released2
mount --move //metro/released /TMPMNT/arcserver1
mount --move //metro/released /TMPMNT/arcserver2
mount --move //metro/released /TMPMNT/arcserver3
mount --move //metro/released /TMPMNT/arcserver4
After this you'll have separate directories for each mounted filesystem, which you can explore and unmount at your leasure.
maybe with umount -f ?
-f Force unmount (in case of an unreachable NFS system). (Requires kernel 2.1.116 or later.)
Or maybe you can do it with umount -l
-l Lazy unmount. Detach the filesystem from the filesystem hierar- chy now, and cleanup all references to the filesystem as soon as it is not busy anymore. (Requires kernel 2.4.11 or later.)
from: http://linux.die.net/man/8/mount
but looking around I found something here.
$ umount.cifs /folder
UPDATE Check the manual of umount.cifs... maybe it could give you an extra hand:
http://www.samba.org/samba/docs/man/manpages-3/umount.cifs.8.html
umount.cifs unmounts a Linux CIFS filesystem. It can be invoked indirectly by the umount(8) command when umount.cifs is in /sbin directory, unless you specify the "-i" option to umount. Specifying -i to umount avoids execution of umount helpers such as umount.cifs. The umount.cifs command only works in Linux, and the kernel must support the cifs filesystem. The CIFS protocol is the successor to the SMB protocol and is supported by most Windows servers and many other commercial servers and Network Attached Storage appliances as well as by the popular Open Source server Samba.