====== Create a new swap ======
Creating an LVM2 Logical Volume for Swap
To add a swap volume group (assuming /dev/VolGroup00/LogVol02 is the swap volume you want to add):
Create the LVM2 logical volume of size 256 MB:
# lvcreate -L 1G -n LogVol02 VolGroup00
Format the new swap space:
# mkswap /dev/VolGroup00/LogVol02
Add the following entry to the /etc/fstab file:
/dev/VolGroup00/LogVol02 swap swap defaults 0 0
Enable the extended logical volume:
# swapon -va
Test that the logical volume has been extended properly:
# cat /proc/swaps # free
swapoff /dev/hda3
mkswap /dev/hda4
swapon /dev/hda4
and edit swap entry in /etc/fstab
==== How to Increase Swap Space in Linux? ====
Check the current swap space
[root@lnxb080 etc]# free -h
total used free shared buff/cache available
Mem: 7.4Gi 1.4Gi 784Mi 384Mi 5.3Gi 5.0Gi
Swap: 2.0Gi 211Mi 1.8Gi
[root@lnxb080 ~]# swapon --show
NAME TYPE SIZE USED PRIO
/dev/dm-6 partition 2G 211.4M -2
[root@lnxb080 ~]# ll /dev/dm-6
brw-rw---- 1 root disk 253, 6 Jan 8 21:00 /dev/dm-6
[root@lnxb080 ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 40G 0 disk
├─sda1 8:1 0 10M 0 part
├─sda2 8:2 0 1005M 0 part
├─sda3 8:3 0 39G 0 part
└─mpathd 253:0 0 40G 0 mpath
├─mpathd1 253:2 0 10M 0 part
├─mpathd2 253:3 0 1005M 0 part /boot
└─mpathd3 253:4 0 39G 0 part
├─rootvg-root 253:5 0 3G 0 lvm /
├─rootvg-swap 253:6 0 2G 0 lvm [SWAP]
├─rootvg-usr 253:7 0 3G 0 lvm /usr
Disable the swap
# swapoff -v /dev/{swap_partition}
Resize the partition
Format the ne swap space
# mkswap /dev/{swap_partition}
Enable the swap
# swapon /dev/{swap_partition}
Check fstab
[root@lnxb080 etc]# cat fstab
...
/dev/mapper/rootvg-swap none swap defaults 0 0
==== Creating a Swap File (instead of partition) ====
Create the swap file with 4GB
# fallocate -l 4G /swap/swapfile01
or
# mkswap -U clear --size 4G --file /swap/swapfile01
Change the permissions
# chmod 600 /swap/swapfile01
Format the swap
# mkswap /swap/swapfile01
Add to /etc/fstab
/swapfile none swap defaults 0 0