LOSETUP(8) System Administration LOSETUP(8) (NAME) losetup - (Loop Devices) (SYNOPSIS) : losetup [loopdev] losetup -l [-a] losetup -j file [-o offset] : losetup -d loopdev ... : losetup -D : losetup [-o offset] [--sizelimit size] [--sector-size size] [--loop-ref name] [-Pr] [--show] -f|loopdev file : losetup -c loopdev (DESCRIPTION) losetup . loopdev . . ( losetup -a) --list . . . --nooverlap --find . --find losetup . . flock(1) . (OPTIONS) KiB (=1024) MiB (=1024*1024) GiB TiB PiB EiB ZiB YiB ( "iB" "K" "KiB" ) KB (=1000) MB (=1000*1000) GB TB PB EB ZB YB size offset . -a, --all . (non-root) . --list . ( --list ) . -d, --detach loopdev... () . 3.7 << >> (lazy device destruction) . EBUSY autoclear . . losetup udevadm settle . -D, --detach-all . -f, --find [file] . file . . --show -f file . -L, --nooverlap . . --find . -j, --associated file [-o offset] file . -o, --offset offset offset . offset . --loop-ref string (reference string). ioctl ( lo_file_name). string . udevd /dev/loop/by-ref . sysfs . (root) (--output +REF ) . --sizelimit size size . size . -b, --sector-size size ( 4.14). . -c, --set-capacity loopdev . -P, --partscan . . --sector-size --partscan . -r, --read-only . --direct-io[=on|off] / (Direct I/O) . off . --direct-io --direct-io=on . --direct-io=off . -v, --verbose (verbose). -l, --list -a . --output --noheadings --raw --json . -O, --output column[,column]... --list . --help . --output-all . -n, --noheadings --list. --raw --list. -J, --json JSON --list. (ENCRYPTION) Cryptoloop dm-crypt . cryptsetup(8) . (EXIT STATUS) losetup 0 . losetup 1 2 . (NOTES) 2.37 losetup ioctl LOOP_CONFIGURE ioctl . ioctl LOOP_SET_FD LOOP_SET_STATUS64 . (ENVIRONMENT) LOOPDEV_DEBUG=all . (FILES) /dev/loop[0..N] /dev/loop-control (EXAMPLE) . # dd if=/dev/zero of=~/file.img bs=1024k count=10 # losetup --find --show ~/file.img /dev/loop0 # mkfs -t ext2 /dev/loop0 # mount /dev/loop0 /mnt ... # umount /dev/loop0 # losetup --detach /dev/loop0 (AUTHORS) Karel Zak Theodore Ts'o . (REPORTING BUGS) . (AVAILABILITY) losetup util-linux . . util-linux 2.41.5 2026-06-16 LOSETUP(8)