We cab increase the RAM SWAP memory by using the following commands but make sure that you have logged in as a root user.
1st) First open the /etc/fstab file and check the volume group used for the swap.
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/dev/mapper/vg_test-lv_swap swap swap defaults 0 0
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In above example the VG is /dev/mapper/vg_test-lv_swap
2nd) Now set the swap off for the VG /dev/mapper/vg_test-lv_swap
swapoff -v /dev/mapper/vg_test-lv_swap
3rd) Create the filesystem for new swap partition
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mkfs.ext3 -b 4568 /dev/sda4
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In above example, we have used /dev/sda4
4th) Create the phyiscal volume
pvcreate /dev/sda4
5th) Check the status for the new free disk space
vgdisplay
6th) Now extend the volume group
vgextend vg_test /dev/sda4
7th) Now extend the size of a logical volume :
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lvresize /dev/mapper/vg_test-lv_swap -L +4G
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As per above command the new RAM swap memory value will be 4GB
8TH) Now format the new swap space:
mkswap /dev/mapper//vg_test-lv_swap
9th) Enable the extended logical volume:
swapon -va
Check the new swap value by using the following command
free -m
If you want to decrease the swap FROM 4G TO 3G then run the following command
lvreduce -L 3G /dev/mapper/vg_test-lv_swap
