Linux Administration Cookbook

Listing swap

Swap is special, and it's more like extended, slow, and somewhat annoying memory than it is disk space.

Swap is used when your system's RAM is full, and the kernel starts to offload infrequently accessed memory onto the disk, where it can be read back at a much slower rate.

Is it time for another holy war? I think it is! Some systems administrators swear by swap and will always make sure their system has at least a few megabytes of space to swap into, even if they've got 256 GB of RAM; other systems administrators say that, if you're using that much RAM and still swapping, you need more RAM. Smile and nod if you're not the person making the decision about whether or not to even have swap—it's not worth it.

We can list what swap ...