Clear off swap

Today I have an issue where my swap is almost full. To check your swap usage:

$ free -m

                    total       used       free     shared    buffers     cached

Mem:          1024        157        866          0         11         48

-/+ buffers/cache:         97        926

Swap:          127         95         32

where -m is for the value to be listed in megabytes.

To clear the swap off, please use below commands (please run as root, or sudo):

# sync && /sbin/sysctl vm.drop_caches=3 && swapoff -a && swapon -a 

where sync is to force changed blocks to disk and update the super block; sysctl vm.drop_caches=3 is to free pagecache, dentries and inodes; swapoff is to turn off swap and swapon is to turn swap back on, obviously :)

p.s. Thanks to linuxnetadmin and linuxinsight for the tips.

And you will get free swap after that:

$ free -m

                    total       used       free     shared    buffers     cached

Mem:          1024        157        866          0         11         48

-/+ buffers/cache:         97        926

Swap:          127         0         127
 

That's all folks.