How To Extend swap size in Linux

How To Extend swap size in Linux

There could be situations where we need to extend the swap. Here i've a situation to extend the swap volume from 8 GB to 16 GB. Lets see how to do that:

Check the cureent Swap status:
[root@exampleserver ~]# free -m
             total       used       free     shared    buffers     cached
Mem:        515671       3101     512569          0         25         77
-/+ buffers/cache:       2998     512672
Swap:         8191          0       8191

Switch off the Swap.
[root@exampleserver ~]# swapoff -a

Extend the swap volume:
[root@exampleserver ~]# lvextend -L +8G /dev/mapper/vg_root-lv_swap
  Size of logical volume vg_root/lv_swap changed from 8.00 GiB (2048 extents) to 16.00 GiB (4096 extents).
  Logical volume lv_swap successfully resized
[root@exampleserver ~]#

Now activate the swap space to take added size. 
[root@exampleserver ~]# mkswap /dev/mapper/vg_root-lv_swap
mkswap: /dev/mapper/vg_root-lv_swap: warning: don't erase bootbits sectors
        on whole disk. Use -f to force.
Setting up swapspace version 1, size = 16777212 KiB
no label, UUID=575854af-d3b0-4aca-926d-484f1ae3655f
[root@exampleserver ~]#

Now Switch on the Swap
[root@exampleserver ~]# swapon -a

Now Check Current swap status.

[root@exampleserver ~]# free -m
             total       used       free     shared    buffers     cached
Mem:        515671       3107     512563          0         25         77
-/+ buffers/cache:       3004     512666
Swap:        16383          0      16383
[root@exampleserver ~]#




If you do not have space to extend LV , then you can create a swap file and add it to swap space. Please click here to see the detailed procedure.