AIX Paging

Recommendations for paging

Creating all paging spaces the same size

Maximum spreading across disks

Make sure they are all online

Avoid shared disks likely to be moved to another system (might require a reboot)

Don’t have dedicated paging disks – when you have a peak in paging you want ALL disks to help out.

To see current paging space use : lsps -a
 
Create paging space

• Use smit lvm
• set size
• set online “now”
• set online at next reboot too

Warning:

• lsps and create paging use different units!!
• use lsps -a -c

We recommend using more paging spaces rather than growing just the one but there is a limit to the number of paging spaces

• A paging space can be increased in size
• If the spaces are different sizes this can be used to make them all the same size.
• Paging spaces are used evenly therefore lots of paging spaces and lots of disks

If a paging space disk fails, the system will halt, on reboot the paging space will be disabled.
If your paging space is not protected by RAID5 or a disk subsystem then you should consider mirroring.

For extra availability – mirror the paging space
Just like mirroring a logical volume (LV)

• smitty lvm + LV + Set LV + Add a copy
• or use command: mklvcopy command

Removing a Paging Space

Impossible – well it was on older AIX versions on newer version sit is possible you will have to check for your version.

• Use: smit lvm
• take Paging Space
• then deactivate it
• then remove it

If you can’t remove it set to be offline at next reboot … wait till you can reboot.