topic Re: swap priority in Operating System - HP-UX

swap priority

Vogra — Mon, 29 Jul 2002 11:22:33 GMT

Hi All!
on HPUX11.00 I created (2nd)swap area with priority 0, but I want to change it to priority 1. The question is: can I change on the fly, With no boot? ...And the change occur immediate?

Re: swap priority

Tore_1 — Mon, 29 Jul 2002 11:58:02 GMT

I dont think so. I tried it out, with
swapinfo -p "priority" "device", but I got
an error message :
swapon: /dev/vg00/lvol2 is already enabled for paging

I'm pretty sure theres no other ways to set swap (and attribute priority) on the fly, so a reboot is strongly indicated.

Re: swap priority

Trond Haugen — Mon, 29 Jul 2002 12:13:21 GMT

No you can't.
The priority is set when the swap is enabled, so changing it requires a reboot. It is usually better for performance to keep swap priority the same for devices with the same "speed". That way the load (if any) will be spread.

Regards,
Trond

Re: swap priority

V. V. Ravi Kumar_1 — Mon, 29 Jul 2002 12:26:45 GMT

hi,
u can change priority, but it is effective only after reboot. use SAM to do it.

regds

Re: swap priority

Vogra — Mon, 29 Jul 2002 12:33:33 GMT

thanx all.

Re: swap priority

John Dvorchak — Tue, 30 Jul 2002 14:10:03 GMT

Once swap is enabled with swapon you are locked into it. You can change the priority but it won't take effect until you reboot. For performance reasons, you may want to leave it at 0 though, if the system memory is pressured and this swap device is on a different disk/controller than your other swap, or this swap device is on a controller/disk that is under utilized.