topic Re: HP-UX Buffer cache's ideal size in Operating System - HP-UX

HP-UX Buffer cache's ideal size

jason_lee — Mon, 17 Nov 2008 06:27:55 GMT

Hi,
Our environment:
1) HP-UX 11.11
2) RAM SIZE = 2GB (yeah, old server)

I noticed from Glance, the following:
i) Sys Mem : 599MB
ii)Buf Cache : 790MB
iii)User Mem : 638MB
iv) Free Mem : 21MB

Looking at above, of course we want to increase the "Free Mem". I'm thinking of tuning the dbc_max_pct, what's the ideal size for the "Buffer Cache", how do I know the current usage now? Any tool that I can find out XYZ of 790MB is being used?

Points for useful suggestion.
Jason.

Re: HP-UX Buffer cache's ideal size

Johnson Punniyalingam — Mon, 17 Nov 2008 06:45:51 GMT

kmtune |grep dbc_max_pct
dbc_max_pct 50 - 50

check below link

http://forums13.itrc.hp.com/service/forums/questionanswer.do?admit=109447627+1226904239443+28353475&threadId=750342

Thx
Johnson

Re: HP-UX Buffer cache's ideal size

Johnson Punniyalingam — Mon, 17 Nov 2008 06:46:43 GMT

another one .. :)

http://forums13.itrc.hp.com/service/forums/questionanswer.do?admit=109447627+1226904353525+28353475&threadId=820986

Re: HP-UX Buffer cache's ideal size

Johnson Punniyalingam — Mon, 17 Nov 2008 06:53:56 GMT

The only way to reliably see buffer cache usage is to run Glance with the "d" window to look at logical (buffered) and physical reads and writes. Look at the second page in the d window for cache hit rates. Writes will normally have a lower hit rate.

Thanks,
Johnson

Re: HP-UX Buffer cache's ideal size

Johnson Punniyalingam — Mon, 17 Nov 2008 07:06:39 GMT

Hi Jason,

smilar thread opened by you .. :)

check this one also dude

http://forums13.itrc.hp.com/service/forums/questionanswer.do?threadId=1071366

Re: HP-UX Buffer cache's ideal size

jason_lee — Mon, 17 Nov 2008 07:23:55 GMT

as shown above