mount: could not find any free loop device

["Andrew" <knoppix@rngresearch.com>]

Dear Klaus et al,

(V6.4.4)
This problem is caused by the present set of loop device files.  This can
be solved by reverting to the set from earlier knoppix versions (i.e.,
/dev/loop[0-7]).  Specifically, removal of the /dev/loop/0 file and the
/dev/loop/ directory fix the problem.

I hope you find this helpful!

Regards,
Andrew


Some details of the behavior of the problem:

root@Microknoppix:/# mkdir /k643
root@Microknoppix:/# mount -t iso9660 -o loop
/media/.../KNOPPIX_V6.4.3DVD-2010-12-20-EN.iso /k643
mount: could not find any free loop device
root@Microknoppix:/# losetup -f
/media/.../KNOPPIX_V6.4.3DVD-2010-12-20-EN.iso
losetup: could not find any free loop device
root@Microknoppix:/# losetup -a
/dev/loop/0: [0801]:16012 (/mnt-system/KNOPPIX/knoppix-data.aes),
encryption aes (type 18)
root@Microknoppix:/# ls -alR /dev/loop*
brw-rw---- 1 root disk 7, 0 Jul 21 06:46 /dev/loop0
brw-rw---- 1 root disk 7, 1 Jul 21 06:46 /dev/loop1
brw-rw---- 1 root disk 7, 2 Jul 21 06:46 /dev/loop2
brw-rw---- 1 root disk 7, 3 Jul 21 06:46 /dev/loop3
brw-rw---- 1 root disk 7, 4 Jul 21 06:46 /dev/loop4
brw-rw---- 1 root disk 7, 5 Jul 21 06:46 /dev/loop5
brw-rw---- 1 root disk 7, 6 Jul 21 06:46 /dev/loop6
brw-rw---- 1 root disk 7, 7 Jul 21 06:46 /dev/loop7

/dev/loop:
total 0
drwxr-xr-x  2 root root    60 May  5  2008 .
drwxrwxrwt 24 root root 18540 Jul 21 06:47 ..
brw-------  1 root root  7, 0 Jul 21 06:46 0
root@Microknoppix:/#

At first, removing the extra device file seems to make things worse:

root@Microknoppix:/# rm /dev/loop/0
rm: remove block special file `/dev/loop/0'? y
root@Microknoppix:/# losetup -a
root@Microknoppix:/# mount -t iso9660 -o loop
/media/.../KNOPPIX_V6.4.3DVD-2010-12-20-EN.iso /k643
mount: Could not find any loop device. Maybe this kernel does not know
       about the loop device? (If so, recompile or `modprobe loop'.)
root@Microknoppix:/# losetup -f
/media/.../KNOPPIX_V6.4.3DVD-2010-12-20-EN.iso
losetup: Could not find any loop device. Maybe this kernel does not know
       about the loop device? (If so, recompile or `modprobe loop'.)

But removing the directory makes everything work perfectly:

root@Microknoppix:/# rmdir /dev/loop
root@Microknoppix:/# losetup -a
/dev/loop0: [0801]:16012 (/mnt-system/KNOPPIX/knoppix-data.aes),
encryption aes (type 18)
root@Microknoppix:/# mount -t iso9660 -o loop
/media/.../KNOPPIX_V6.4.3DVD-2010-12-20-EN.iso /k643
root@Microknoppix:/# ls /k643
KNOPPIX  autorun.bat  autorun.inf  autorun.pif  boot  cdrom.ico
index.html
root@Microknoppix:/#