Linux Kernel in a Nutshell

Name

SOFTWARE_SUSPEND — Software suspend

Enable machine suspension.

When the machine is suspended, an image is saved in your active swap. Upon next boot, pass the resume=/dev/swappartition argument to the kernel to have it detect the saved image, restore memory state from it, and continue to run as before. If you do not want the previous state to be reloaded, use the noresume kernel argument. However, note that your partitions will be fsck'd and you must issue mkswap on your swap partitions again. The procedure does not work with swap files.

Right now you may boot without resuming and then resume later, but in the meantime you cannot use those swap partitions/files which were involved in suspending. In this case, also, there is a risk that buffers on disk won't match with saved ones.

For more information take a look at Documentation/power/swsusp.txt.