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Tuesday, 5 March 2013

How to increase SWAP space in Ubuntu?

All command should be run with root privileges,.

1. Create empty file:
This file will contain virtual memory contents so make file big enough for your needs. This one will create 1Gb file which means +1Gb swap space for your system:
dd if=/dev/zero of=/media/swapdd/swapfile.img bs=1024 count=1M

If you want to make 3Gb file then change count value to count=3M. See man dd for more information.

2. Bake swap file:
Following command is going to make "swap filesystem" inside your fresh swap file.
mkswap /media/swapdd/swapfile.img

3. Bring up on boot:
To make sure that your new swap space is activated while booting up computer you should add it to filesystem configuration file /etc/fstab.
/media/swapdd/swapfile.img swap swap sw 0 0

4. Activate:
You can either reboot your computer or activate new swap file by hand with following command:
swapon /media/swapdd/swapfile.img

You can use following commands to check your new swap and confirm that it is active:
cat /proc/swaps
Filename Type Size Used Priority
/media/swapdd/swapfile.img file 8388604 2724 -1

grep 'Swap' /proc/meminfo
SwapCached: 4772 kB
SwapTotal: 8388604 kB
SwapFree: 8355812 kB