umount: /media/cdrom0: device is busy

[gavroche]

I have encountered the same problem several times:
after having mounted the CD-ROM or USB and finished
using it, I cannot unmount it because "...it is busy..."
etc. So, the first thing to do is to ensure that you are
not browsing the directory where the device has been
mounted on, and also ensure that there are no processes
doing the same. The latter is a bit tricky, because you
might think there is no process, yet there might be.
You can check this using the lsof command. In particular,
the problem in my case (Debian 3.1 , Kernel 2.4.27, KDE 3.3),
was that there was a setting enabled in Konqueror
whereby it remembers the last (not sure how many) directories
you have browsed, *even after you have closed the window*.
This enhances performance but it also prevents you from
unmounting your device. To disable this setting open:

Konqueror>Settings>Configure Konqueror>Performance
and in the Preload section choose
Maximum number of instances kept preloaded =0

Hopefully this will be useful.

[mattydee]

I have encountered the same problem several times:
after having mounted the CD-ROM or USB and finished
using it, I cannot unmount it because "...it is busy..."
etc. So, the first thing to do is to ensure that you are
not browsing the directory where the device has been
mounted on, and also ensure that there are no processes
doing the same. The latter is a bit tricky, because you
might think there is no process, yet there might be.
You can check this using the lsof command. In particular,
the problem in my case (Debian 3.1 , Kernel 2.4.27, KDE 3.3),
was that there was a setting enabled in Konqueror
whereby it remembers the last (not sure how many) directories
you have browsed, *even after you have closed the window*.
This enhances performance but it also prevents you from
unmounting your device. To disable this setting open:

Konqueror>Settings>Configure Konqueror>Performance
and in the Preload section choose
Maximum number of instances kept preloaded =0

Hopefully this will be useful.

Very useful! Thank you!
I was using

lsof | grep /mnt/usb/ipod/whatever

and kept noticing that konqueror was the culprit, but didn't know how to fix this behavior. I had to use kill to terminate konqueror.

Thanks again.

[coolnezz]

one way around this is to use

umount -l <mounted fs ie /mnt/cdrom0>

the -l unlinks /mnt/cdrom0 from fstab, at which point any apps
with a lock on this directory cannot access it anymore.

umount will then unmount the device normally

this is the way i use to get around the "device is busy" thing

meh. just read the man pages for umount it will give a better explanation

This worked for me... thanks!