How to set up swap space? raspberry

Raspbian uses dphys-swapfile, which is a swap-file based solution instead of the "standard" swap-partition based solution. It is much easier to change the size of the swap.

The configuration file is:

/etc/dphys-swapfile

The content is very simple. By default my Raspbian has 100MB of swap:

CONF_SWAPSIZE=100

If you want to change the size, you need to modify the number and restart dphys-swapfile:

/etc/init.d/dphys-swapfile stop
/etc/init.d/dphys-swapfile start

Edit: On Raspbian the default location is /var/swap, which is (of course) located on the SD card. I think it is a bad idea, so I would like to point out, that the /etc/dphys-swapfile can have the following option too: CONF_SWAPFILE=/media/btsync/swapfile

I only problem with it, the usb storage is automounted, so a potential race here (automount vs. swapon)