Adding SWAP space by extending LVM volume

This blog post will guide you on how we can extend the swap space for an existing LVM volume. For using this method LVM volume must have free capacity to accommodate the new swap space. If the space is not available in an existing LVM then this method is not helpful. Check the existing swap :

[root@racnode1 yum.repos.d]# grep swap /etc/fstab
/dev/mapper/ol_racnode1-swap none                    swap    defaults        0 0
[root@racnode1 yum.repos.d]# ls -l /dev/mapper/ol_racnode1-swap
lrwxrwxrwx 1 root root 7 Mar 15 23:00 /dev/mapper/ol_racnode1-swap -> ../dm-1
[root@racnode1 yum.repos.d]# ls -al /dev/mapper/ol_racnode1-swap
lrwxrwxrwx 1 root root 7 Mar 15 23:00 /dev/mapper/ol_racnode1-swap -> ../dm-1
[root@racnode1 yum.repos.d]#

Before extending the swap volume disable the swap:

[root@racnode1 yum.repos.d]# swapoff -v /dev/mapper/ol_racnode1-swap
swapoff /dev/mapper/ol_racnode1-swap
[root@racnode1 yum.repos.d]# 

Now extend the LVM swap volume:

[root@racnode1 yum.repos.d]# lvextend -L +32G /dev/mapper/ol_racnode1-swap
  Size of logical volume ol_racnode1/swap changed from 4.00 GiB (1024 extents) to 36.00 GiB (9216 extents).
  Logical volume ol_racnode1/swap successfully resized.
[root@racnode1 yum.repos.d]# 

Configure swap on LVM volume:

 [root@racnode1 yum.repos.d]# mkswap /dev/mapper/ol_racnode1-swap
mkswap: /dev/mapper/ol_racnode1-swap: warning: wiping old swap signature.
Setting up swapspace version 1, size = 36 GiB (38654701568 bytes)
no label, UUID=620438f7-ca46-4a3e-899c-7aa999aa7bc2
[root@racnode1 yum.repos.d]# 

Enable SWAP LVM volume:

[root@racnode1 yum.repos.d]# swapon -v /dev/mapper/ol_racnode1-swap
swapon: /dev/mapper/ol_racnode1-swap: found signature [pagesize=4096, signature=swap]
swapon: /dev/mapper/ol_racnode1-swap: pagesize=4096, swapsize=38654705664, devsize=38654705664
swapon /dev/mapper/ol_racnode1-swap
[root@racnode1 yum.repos.d]#

The initial configured swap size was 4 GB and after extending the LVM volume the new swap size is 36GB. Hope it helps and thanks for reading 😊 Regards, ZAHEER