UNIX : Changing swap value on HP-UX and AIX

I don't like messing with a prod server's swap value unless there is a direct request from a customer

Here's how you do it on HP-UX and AIX. I trust you have your CR raised

HP-UX

The default value for swappiness is 60. You can alter it temporarily (until you next reboot) by typing as root

echo 50 > /proc/sys/vm/swappiness

If you want to alter the swap value change permanently then you need to change the vm.swappiness parameter in the /etc/sysctl.conf file

Step 1: check what is the current value for swap

sudo cat /proc/sys/vm/swappiness

(It should give a number 60 here)

Step 2: change to a lower number

sudo sysctl -w vm.swappiness=5

Step 3: check again

sudo cat /proc/sys/vm/swappiness

(Now, it should give a number 5 here)

Step 4: append the line vm.swappiness=5 in file /etc/sysctl.conf using vi editor

AIX

Things are easier on AIX with the use of smitty. I used AIX version 5.3

1. Check the current paging and swapspace value

# lsps -a

# pstat -s

2. Run smitty and make changes on the fly

# smit pgsp-----to increase/decrease paging

3. Check paging and swapspace value again

# lsps -a

# pstat -s

4. To add paging space

# smit lvm---paging space---add

or

#smit mkps