Why not just create a swap file in unused space? Quick and easy:
For Adding a 512MiB swap
Creating a file for 512MiB adjust size as desired to the size you want:
We will create a /mnt/512MiB.swap swap file and set the permissions so that users cannot read it directly.
sudo fallocate -l 512m /mnt/512MiB.swap
sudo chmod 600 /mnt/512MiB.swap
fallocate length suffixes are: k, m, g, t, p, e (See man fallocate).
By default your swap file may be created world readable. We set the 600 mode permissions in order to prevent users from being able to read potentially sensitive information from the swap file.
If fallocate fails with "fallocate failed: Operation not supported" as it currently does on my Maverick machine, you can do this the old way, again 512 mebibytes:
sudo dd if=/dev/zero of=/mnt/512MiB.swap bs=1024 count=524288
sudo chmod 600 /mnt/512MiB.swap
Formatting that file to create a swapping device:
sudo mkswap /mnt/512MiB.swap
Adding the swap to the running system:
sudo swapon /mnt/512MiB.swap
The additional swap is now available and can be seen by cat /proc/meminfo
or free
Making the change permanent:
Edit the /etc/fstab:
gksudo gedit /etc/fstab
Add this line at the end of the file:
/mnt/512MiB.swap none swap sw 0 0
Save. After the next reboot the swap will be used automatically.
Example of making a swap file
This is an example of making and using a swap file on a computer with no swap partition.
Enter the command below and your password when prompted:
sudo fallocate -l 512m /mnt/512MiB.swap
Then this command:
sudo mkswap /mnt/512MiB.swap
Output will be similar to the below.
Setting up swapspace version 1, size = 536866 kB
no label, UUID=dd6a01c8-93f0-41e0-9b7a-306956d8821b
Then issue the command:
sudo swapon /mnt/512MiB.swap
The following command shows you the results:
cat /proc/meminfo
MemTotal: 499496 kB
MemFree: 9156 kB
Buffers: 4748 kB
Cached: 233140 kB
SwapCached: 724 kB
Active: 254432 kB
Inactive: 157920 kB
HighTotal: 0 kB
HighFree: 0 kB
LowTotal: 499496 kB
LowFree: 9156 kB
SwapTotal: 524280 kB
SwapFree: 523556 kB
Dirty: 128 kB
Writeback: 0 kB
Mapped: 243420 kB
Slab: 20672 kB
CommitLimit: 774028 kB
Committed_AS: 648680 kB
PageTables: 2224 kB
VmallocTotal: 524280 kB
VmallocUsed: 5708 kB
VmallocChunk: 518176 kB
Make the change permanent by editing your fstab
gksudo gedit /etc/fstab
Add the line:
/mnt/512MiB.swap none swap sw 0 0
A simple command to see usage is:
free
total used free shared buffers cached
Mem: 499496 479488 20008 0 8256 215892
-/+ buffers/cache: 255340 244156
Swap: 524280 3856 520424
Then, after running a few more programs...
free
total used free shared buffers cached
Mem: 499496 492768 6728 0 1240 142336
-/+ buffers/cache: 349192 150304
Swap: 524280 53384 470896
Next, reboot to make sure it will work consistently.
free
total used free shared buffers cached
Mem: 499496 493136 6360 0 7528 174700
-/+ buffers/cache: 310908 188588
Swap: 524280 17148 507132
Source: https://help.ubuntu.com/community/SwapFaq
Best Answer
You need to edit
/etc/fstab
and add the new swap partition.You need to add a line that looks like
and you get the UUID using the command
(substitute
/dev/sda3
with the appropriate device name; in order to see the appropriate device name, we can uselsblk
- as said here).Related: