- List loop devices with detailed info:losetup -a- Attach a file to a given loop device:sudo losetup /dev/[loop] /[path/to/file]- Detach all loop devices:sudo losetup -D- Detach a given loop device:sudo losetup -d /dev/[loop]
losetup -l [-a]
losetup -j file [-o offset]
Detach a loop device:
losetup -d loopdev...
Detach all associated loop devices:
Print the name of the first unused loop device:
Set up a loop device:
losetup [-o offset] [--sizelimit size] [-Pr] [--show] -f|loopdev file
Resize a loop device:
losetup -c loopdev
losetup is used to associate loop devices with regular files or block devices, to detach loop devices, and to query the status of a loop device. If only the loopdev argument is given, the status of the corresponding loop device is shown. If no option is given, all loop devices are shown.
Note that the old output format (i.e. losetup -a) with comma-delimited strings is deprecated in favour of the --list output format.
It's possible to create more independent loop devices for the same backing file. This setup may be dangerous, can cause data loss, corruption and overwrites. Use --nooverlap to avoid this problem.
The size and offset arguments may be followed by the multiplicative suffixes KiB (=1024), MiB (=1024*1024), and so on for GiB, TiB, PiB, EiB, ZiB and YiB (the "iB" is optional, e.g., "K" has the same meaning as "KiB") or the suffixes KB (=1000), MB (=1000*1000), and so on for GB, TB, PB, EB, ZB and YB.
Cryptoloop is no longer supported in favor of dm-crypt. For more details see cryptsetup(8).
losetup returns 0 on success, nonzero on failure. When losetup displays the status of a loop device, it returns 1 if the device is not configured and 2 if an error occurred which prevented determining the status of the device.
The following commands can be used as an example of using the loop device.
Karel Zak <email@example.com>, based on the original version from Theodore Ts'o <firstname.lastname@example.org>
The losetup command is part of the util-linux package and is available from ftp://ftp.kernel.org/pub/linux/utils/util-linux/.