TIPS: Linux Commands to add swap space

1) Login as "root" user.

2) Execute command "/sbin/swapon -s" (Remove quotations) and you will get current swap size details:

Sample OutPut:
[root@dev /]# /sbin/swapon -s
Filename                                Type            Size    Used    Priority
/dev/mapper/VolGroup00-LogVol01         partition       2064376 0       -1

3) Execute below command to create new swap space with 2048MB space

dd if=/dev/zero of=/home/swapfile bs=2048 count=1048576

Sample OutPut: 

[root@dev /]# dd if=/dev/zero of=/home/swapfile bs=2048 count=1048576
1048576+0 records in
1048576+0 records out
2147483648 bytes (2.1 GB) copied, 13.8048 seconds, 156 MB/s

4) Execute below commands to create swap file:

/sbin/mkswap /home/swapfile 

/sbin/swapon /home/swapfile 

Now, Swap size is increased to 4 GB.

5) To check the swap space execute "/sbin/swapon -s"

Sample OutPut: 

[root@dev /]# /sbin/swapon -s

Filename                                Type            Size    Used    Priority

/dev/mapper/VolGroup00-LogVol01         partition       2064376 0       -1

/home/swapfile                          file            2097144 0       -2

-- Siva Pokuri.