topic Re: nbuf 100% utilised. in Operating System - HP-UX

nbuf 100% utilised.

aruns_s — Tue, 26 Sep 2006 00:11:25 GMT

Hi gurus,
one of my HP box is reporting nbuf is 100% thru glance.Will it cause any performance issues?What can i do to increase nbuf?

Many thanks

Re: nbuf 100% utilised.

sudhapage — Tue, 26 Sep 2006 00:36:22 GMT

Hi

Please Check with below mentioned old thread.

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=964961&admit=-682735245+1159248847331+28353475

Regards,
Sudhakaran.K

Re: nbuf 100% utilised.

Steven E. Protter — Tue, 26 Sep 2006 01:32:21 GMT

Shalom,

100% utilization with no impact on response time is a non-issue. I'd only increase that parameter if there is a specific reason to do so, otherwise you are wasting the resources.

For long term tracking: http://www.hpux.ws/system.perf.sh

SEP

Re: nbuf 100% utilised.

Bill Hassell — Tue, 26 Sep 2006 06:44:29 GMT

Don't touch nbuf kernel parameter. There are four parameters that control the buffer cache:

bufpages nbuf dbc_min_pct dbc_max_pct

When the kernel parameters bufpages and nbuf are initially set to 0, then the dbc parameters set the buffer cache size. bufpages can be set to the number of 4k pages that are desired and this will disable the dbc (dynamic buffer cache). However, nbuf is quite tricky to size, especially when bufpages is not 0. In SAM look at the Help On Context for bufpages and nbuf (or look at http://docs.hp.com/en/TKP-90202/TKP-90202.pdf ) for the gory details.

NOTE: at 11.23, bufpages and nbuf are removed from the tunable kernel parameters.

As for Glance, the numbers for nbuf percentage were changed to "na" a long time ago so your version of Glance (or the OS) is way out of date.