How to change swap priority
Linux kernel 2.4 and later can handle multiple swap spaces up to 32 swap space, If you use multiple swap files and partitions and you want to prioritize which spaces are used first, you can do it by altering the priority no of swap files and partitions to boost the virtual memory. By default the priorities are assigned in the order that the swap spaces are added, where -1 is a higher priority number than -2.
Run the following command to see the swap files or partitions priority.
[ root @ leolinux ~ ]# swapon -s
Filename Type Size Used Priority
/dev/hda6 partition 4095996 57788 -1
/var/swapfile file 1048576 0 -2
First you need to deactivate the used swap partition or file in order to change the priority temporary.
[ root @ leolinux ~ ]# swapoff /dev/hda6
To change the priority -2 to 10
[ root @ leolinux ~ ]# swapon -p 10 /dev/hda6
To check priority
[ root @ leolinux ~ ]# swapon -s
Filename Type Size Used Priority
/dev/hda6 partition 4095996 57788 10
/var/swapfile file 1048576 0 -2
To change the priority permanently run the follwoing steps.
[ root @ leolinux ~ ]# swapoff /dev/hda6
Edit /etc/fstab file.
[ root @ leolinux ~ ]# vim /etc/fstab
/dev/hda6 swap swap defaults,pri=10 0 0
ESC
:wq!
To activate swap partitions or swap files .
[ root @ leolinux ~ ]# swapon -a
To check priority.
[ root @ leolinux ~ ]# swapon -s
Filename Type Size Used Priority
/dev/hda6 partition 4095996 57788 10
/var/swapfile file 1048576 0 -2