losetup

sets up and controls loop devices, which allow regular files to be

TLDR

List all loop devices

$ losetup -a

Attach file to loop device

$ sudo losetup /dev/loop0 /path/to/file

Attach to free device with partition scan

$ sudo losetup --show -P -f /path/to/file

Attach read-only

$ sudo losetup -r /dev/loop0 /path/to/file

Detach all loop devices

$ sudo losetup -D

Detach specific loop device

$ sudo losetup -d /dev/loop0

SYNOPSIS

losetup [OPTIONS] [loopdev] [file]

DESCRIPTION

losetup sets up and controls loop devices, which allow regular files to be accessed as block devices. This is commonly used for mounting disk images, ISO files, or encrypted containers.

PARAMETERS

-a, --all

Show status of all loop devices

-f, --find

Find the first unused loop device

-P, --partscan

Scan the partition table on the device

-r, --read-only

Set up a read-only loop device

-d, --detach

Detach specified loop device

-D, --detach-all

Detach all associated loop devices

--show

Print the loop device name after setup

-o, --offset bytes

Start at offset into the file

--sizelimit bytes

Limit the size of the loop device

CAVEATS

Loop devices require root privileges to create and detach. The kernel has a limited number of loop devices available (configurable). Always detach loop devices when finished to free resources.

HISTORY

losetup is part of the util-linux package, providing loop device management on Linux systems.