value for swap

[Felix Tabares]

which is the critical value for swapping in an HP-UX in 11.23 and the optimum value?
is more the 85%?

Value which is recommended by HP for use of swap, for server performance?

[singh sanjeev]

keep swap more then the physical Memory.[double]

[Felix Tabares]

thanks

but I really want to know what value you should put in a monitor system, what is the maximum value in %.

which would be a suggested value 80% 90% or more

[Ricardo Pagán]

if you use a monitoring system nagios type, it is recommended to let you know when the swap rate is higher than 80% to have discretion to increase that percentage if necessary.

[chris huys_4]

Hi Felix,

Check this thread out.

https://forums13.itrc.hp.com/service/forums/questionanswer.do?threadId=1449580

Were it talks about lotsfree, thats when the system will begin paging out memory to free up physical RAM.

Personally, while 11.23 for f.e. begins only to page to swapdevice, swapping doesnt really happen anymore, at 1/64 of physical memory which is around, (100 - (0.015625 * 100) = (100 - 1.5% ) = 98.5 % of physical ram, I would probably begin to watch closely to how physical ram gets filled up from the 90% mark, to have some kind of buffer in place.

If user processes/kernel/buffercache stabilize around 90% of physical ram, all is good, if there is over time a gradually increase of physical ram used by f.e. userprocesses, because the number of users of an application is gradually increasing over time and passing the 90% of physical ram usage, probably the system will have performance issues in the future and it might be prudent to order more RAM on beforehand, or take measures to stop the userprocesses from taking more memory, f.e. through prohibiting new users to use the servers application..

Greetz,
Chris

[Hakki Aydin Ucar]

I recommend to have this doc. that is a good guide.