topic Re: umount cdrom in Operating System - Linux

umount cdrom

juno2 — Thu, 06 Nov 2003 21:42:25 GMT

I have a cdrom mounted to /mnt/scd0 , but when umount it , it pop the message "device is busy" , i tried "fuser -k /dev/scd0 " or " lsof /dev/scd0 " , no any output , i check that it should no other system mounting it , can suggest what can i umount it? thx.

Re: umount cdrom

Martin P.J. Zinser — Thu, 06 Nov 2003 21:49:28 GMT

Which directory are you located in when you try this? As long as someone did a cd /mnt/scd0 the umount will not work.

Re: umount cdrom

juno2 — Thu, 06 Nov 2003 22:17:34 GMT

thx Martin , yes I know I can't run the umount on the cdrom path , i do it at other path but still fail , can suggest what is wrong in my system ? thx.

Re: umount cdrom

Stuart Browne — Thu, 06 Nov 2003 22:32:22 GMT

A few things to do.

Change to your home directory.

Ensure that it is still mounted ('mount').

Try unmounting both the mount path (usually /dev/cdrom), and the dev path (/dev/scd0).

Try 'lsof' on both the device, and the mount path. If it's in use, it *WILL* show something.

Re: umount cdrom

Martin P.J. Zinser — Thu, 06 Nov 2003 22:45:01 GMT

I agree with Stuart, try lsof | grep scd0, since it seems your CD Rom is mounted on /mnt/scd0.

lsof /dev/scd0 will not work since it does display the files, not the file systems.

Greetings, Martin

Re: umount cdrom

Steven E. Protter — Thu, 06 Nov 2003 23:31:05 GMT

Most common cause of not being able to umount a cdrom: As stated, there is someone on the mountpoint.

At this point, you've tried everything. Boot the box and be careful next time. Review cron scripts for problems.

SEP

Re: umount cdrom

juno2 — Fri, 07 Nov 2003 00:47:59 GMT

when I re-mount the cdrom , it pop

mount: block device /dev/scd0 is write-protected, mounting read-only
mount: /dev/scd0 already mounted or /mnt/cdrom busy
mount: according to mtab, /dev/scd0 is already mounted on /mnt/cdrom

so I sure the cdrom is mounted , on the other hand , i use "lsof |grep scd0 " but no any output , can suggest the solution except reboot the system ? thx.

Re: umount cdrom

juno2 — Fri, 07 Nov 2003 01:51:27 GMT

I remove the entry on /etc/mtab and it is Ok now. thx all help .

Re: umount cdrom

Lawrence Staberg — Mon, 10 Nov 2003 11:13:04 GMT

My experience with this symptom is that the kernal doesn't release control of the mount device after the device has been exported and mounted on an externel system..
I've never seen the problem without the exporting step..

A safer/cleaner way to unmount the cdrom is:

service nfs stop
unmount /dev/scd0
service nfs start

Re: umount cdrom

Elmar P. Kolkman — Wed, 12 Nov 2003 03:03:20 GMT

Next time try the fuser on the whole filesystem (/mnt/cdrom in your case) instead of on the device... fuser -m /mnt/cdrom should do the trick.

Re: umount cdrom

Madhu Sudhan_1 — Wed, 12 Nov 2003 07:22:24 GMT

Check if the mount point is nfs exported.

Re: umount cdrom

Alexander M. Ermes — Fri, 14 Nov 2003 03:20:14 GMT

Hi there.
Just a short note and question to all :
I know, that there is a tool for a scsi reset on HP-UX. Is there one, that could be used on Linux ?
In HP-UX you give the parameter of the raw device ( of cdrom or disk ) to scsireset and that unmounts your cdrom.
Rgds
Alexander M. Ermes

Re: umount cdrom

Madhu Sudhan_1 — Fri, 14 Nov 2003 08:30:57 GMT

Alex,
If you want to send scsi reset in Linux, use
cdrecord -reset dev=. This command sends the scsi reset.
Thank you,
Madhu

Re: umount cdrom

Michael Schulte zur Sur — Sat, 15 Nov 2003 06:00:41 GMT

Hi,

I am wondering too. I allways use fuser on the mountpoint and not the device.

greetings

Michael

Re: umount cdrom

Michael Schulte zur Sur — Wed, 19 Nov 2003 12:18:58 GMT

Hi juno2,

if your problem is solved, could you please award some points, who could help you?

greetings,

Michael

Re: umount cdrom

John Meissner — Mon, 24 Nov 2003 11:07:45 GMT

did you try umount -f cdrom ?

-f is force