mkswap

TLDR

Set up a swap area

$ sudo mkswap /dev/sdXY

Check for bad blocks before creating swap

$ sudo mkswap -c /dev/sdXY

Set a label for the swap partition

$ sudo mkswap -L swap_label /dev/sdXY

Set a specific UUID

$ sudo mkswap -U random /dev/sdXY

Create a swap file of specific size

$ sudo mkswap -s 4G -F /path/to/swapfile

SYNOPSIS

mkswap [options] device [size]

DESCRIPTION

mkswap sets up a Linux swap area on a device or in a file. The device can be a disk partition or a regular file. After creation, use swapon to enable the swap area.

PARAMETERS

-c, --check

Check the device for bad blocks before creating swap area

-f, --force

Force creation even if the device has a detected filesystem

-L, --label LABEL

Specify a label for the swap area (for use with swapon -L)

-p, --pagesize SIZE

Specify page size in bytes

-U, --uuid UUID

Specify UUID (clear, random, time, or specific UUID value)

-v, --swapversion VERSION

Specify swap area version (only version 1 supported)

-e, --endianness ENDIAN

Specify endianness (native or little)

-o, --offset OFFSET

Offset for swap header in device

-s, --size SIZE

Size of swap file (with -F)

-F, --file

Create swap file instead of setting up existing file

--verbose

Print verbose messages

CAVEATS

The device or file must not be in use when running mkswap. For swap files on btrfs, special handling is required. Always run swapon after mkswap to activate the swap area.

HISTORY

mkswap is part of util-linux. Swap space provides virtual memory when physical RAM is exhausted.