From MEPIS Documentation Wiki
In case you don't want to repartition your drive you can still use swap by creating a swap file following these steps:
- Find a nice, out of the way place to create this (/var/run/ might be a good choice), cd to that directory and become root
- Create 1GB swap file (you can use other size, 512MB for example, the maximum size is 2GB):
dd if=/dev/zero of=swapfile bs=1024 count=1000000 mkswap swapfile swapon swapfile
- You need to add this line at the beginning of /etc/fstab file in order to have the swap activated automatically after each reboot:
/var/run/swapfile swap swap rw 0 0
A swap file has lower performance than a swap partition, but it is easier to create and change its size according to your needs.