The programs s2disk and s2both can be used to save the state of the whole system to a swap partition or file and power off or suspend your system. After restarting your system it will be put back in the exact system state you left it (this is sometimes called hibernation).

In the case of using a swap file you will have to specify the location of the swap file's header as the offset from the beginning of the partition that contains the swap file. The swap-offset utility can be used to determine this value.