swapon

swapon/swapoff enable/disable devices and files for paging and swapping and it is included on the mount package.

• Man page: http://man7.org/linux/man-pages/man8/swapon.8.html

• swapon -s or swapon --show

swapon --show
NAME      TYPE      SIZE   USED PRIO
/dev/dm-2 partition 976M 974.8M   -2

swapon --show
(No output if not swap active)

 swapon  -s
 Filename				Type		Size	Used	Priority
 /swap.img                              	file    	2023420	104312	-2

• cat /proc/swaps

 Oct 12 12:55:03 SERVER swapon[449]: swapon: /swap.img: swapon failed: Read-only file system

Related terms

• free
• Memory: sar -r
• Swap: sar -S
• sar -W (Swapping)
• /etc/fstab and /proc/swaps
• systemctl --type swap
• mkswap

See also

• Swap, swapon, swapoff, mkswap, swaplabel, free,sar -r, sar -S, sar -W, vmstat, vm.swappiness, /proc/swaps, /etc/fstab, Add a swap disk, systemd.swap
• File systems: mount, umount, findmnt, find, swapon, swapoff, UUID, blkid, mount options: /etc/fstab, udisksctl mount, guestmount, /proc/mounts, fstrim, systemd-mount, defaults
• Memory: memory pages, RAM, virsh Memory Commands, OOM, meminfo, vmstat, NAND, DDR, lsmem, /dev/shm, /proc/meminfo, sar -r, IOMMU, pmem, Memory management, Garbage collector, THP, Linux Huge Page TLB