unmount: /cdrom device is busy error and solution

last updated in Categories , , , , , , ,

Q. I am trying to unmount remotely hosted Linux server. I have CD mounted and when ever I type command umount /cdrom or umount /dev/cdrom I get an error that read as follows:
unmount: /cdrom device is busy


How do I solve this problem?

A. In order to solve this problem. Run umount command as follows:
# cd /
# umount /cdrom

If problem still continues then forcefully unmount the cdrom:
# cd /
# fuser -km /cdrom

OR try the following command:
# cd /
# umount -l /mnt

See also:


Posted by: Vivek Gite

The author is the creator of nixCraft and a seasoned sysadmin, DevOps engineer, and a trainer for the Linux operating system/Unix shell scripting. Get the latest tutorials on SysAdmin, Linux/Unix and open source topics via RSS/XML feed or weekly email newsletter.

2 comment

  1. What happens basically, is that Linux will not allow you to unmount a device that is busy. There are many reasons for this, but the most important one is to prevent data loss.

    Next time you are stuck with this message, try the following command to find out what processes have activities on the device/partition

    My primary optical drive is /dev/hda, and I would do a (as root)

    lsof -b | grep “/dev/hda”

    Of which the result is

    k3b 30396 andy 19r BLK 3,0 6545 /dev/hda

    This tells me that user andy has a process running (k3b) that is using the primary optical drive (hda)

    As soon as that program terminates its task, the device will no longer be busy and I can unmount it.

    For more information, see man lsof

  2. hello non of these opetions really worked i am trying to install backtrack r3 and it gives me the error that the partition cannot be unmounted and it says /cdrom

    Still, have a question? Get help on our forum!