- using
fdisk
(partition type 82, "Linux swap").
Format the partition checking for bad blocks, for example:
mkswap -c /dev/hda4
You have to substitute /dev/hda4 with your partition name. Since I did not specify the partition size, it will be automatically detected.
Enable the swap, for example:
swapon /dev/hda4
To have the swap enabled automatically at bootup, you have to include the appropriate entry into the file /etc/fstab, for example:
/dev/hda4 swap swap defaults 0 0
If you ever need to disable the swap, you can do it with (as root):
swapoff /dev/hda4
5.2.13.2 Swap files
Swapping to files is usually slower than swapping to a raw partition, so this is not the recommended permanent swapping technique. Creating a swap file, however, can be a quick fix if you temporarily need more swap space. You can have up to 8 swap files, each with size of up to 16 MB. Here are the steps for making a swap file:
Create a file with the size of your swap file:
dd if=/dev/zero of=/swapfile bs=1024 count=8192
This physically creates the swap file /swapfile, the block size is 1024 bytes, the file contains 8192 blocks, the total size is about 8 MB. [The dd command copies files. In the example above, the input file (if) was /dev/zero, the output file (of) was /swapfile . You cannot use the cp (copy) command for creating a swap file because the swap file must be physically continuous on the hard drive.]
Set up the file with the command:
mkswap /swapfile 8192
Force writing the buffer cache to disk by issuing the command:
sync
Enable the swap with the command:
swapon /swapfile
When you are done using the swap file, you can turn it off and remove:
swapoff /swapfile
rm /swapfile
You may also want to see the nice info written by Linus Torvalds himself:
man mkswap
