Creating additional loop devices

If you receive the error message mount: could not find any free loop device, you need to create additional loop devices.

RHEL 5 and RHEL 4 example

The loop module on RHEL 5 and RHEL 4 allows 8 loop devices by default. To increase the number of loop devices to 64, for example, add the following to /etc/modprobe.conf:
options loop max_loop=64

The maximum value of max_loop is 256.

$ ls -l /dev/loop* | wc -l
8

On RHEL 5 and RHEL 4 systems, reloading the loop module will cause the changes (i.e., increasing or decreasing loop devices) in max_loop to take effect.

# /sbin/rmmod loop
# /sbin/modprobe loop

RHEL 3 example

The loop module allows 8 loop devices by default. To increase the number, add the following to /etc/modules.conf:
options loop max_loop=64

The maximum value of max_loop is 256.

$ ls -ld /dev/loop* | wc -l
16

/dev/loop only contains 16 devices, so we need to create additional /dev/loop entries.

# for NUM in $(seq 16 63) ; do mknod -m 0660 /dev/loop$NUM b 7 $NUM ; chown root:disk /dev/loop$NUM; done

The loop module must be removed and reloaded.

# /sbin/rmmod loop
# /sbin/modprobe loop

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