topic Re: nbuf setting in Operating System - HP-UX

nbuf setting

aaronleung_1 — Wed, 13 Mar 2002 02:07:53 GMT

Dear all,

Our L2000 hp-ux server running hp-ux 11.00 with 4GB RAM
we are using oracle db and have about 1200 concurrent user to access it.
The figure for nbuf (from glance) is 5444 and usage is 100%. Do I need to increate nbuf figure and what is this usage ?

--------
Proc Table (nproc) 2112 873 41 41
File Table (nfile) 33738 7126 21 21
Shared Mem Table (shmmni) 512 10 2 2
Message Table (msgmni) 2112 2 0 0
Semaphore Table (semmni) 10560 25 0 0
File Locks (nflocks) 2112 10 0 1
Pseudo Terminals (npty) 256 1 0 0
Buffer Headers (nbuf) 5544 5544 100 100
------------------------------------

Regard,
Aaron

Re: nbuf setting

Michael Tully — Wed, 13 Mar 2002 02:20:36 GMT

How much buffer cache is your system using?

In the link below is a full explanation on 'nbuf'

http://www.docs.hp.com/hpux/onlinedocs/os/KCparam.Nbuf.html

Re: nbuf setting

aaronleung_1 — Wed, 13 Mar 2002 03:35:51 GMT

the current buffer cache is 131072
is it enough

Re: nbuf setting

Michael Tully — Wed, 13 Mar 2002 04:06:11 GMT

Depending on your system setup there is no need
to have any more than 300Mb buffer cache. So,
if you have say 4Gb of RAM, you would to only
set up 7% as your maximum and perhaps 2% as
your minimum. Below are the kernel parameters
for these.

dbc_max_pct 7
dbs_min_pct 2

I'm not sure of the figure of 131072 you have
identified... Is this a snapshot from glance?
The easiest way to find out what the current
parameters are is to look in sam. How you get
the current available is to look in glance and
then press F3 for Mem Rpt.

Michael

Re: nbuf setting

Michael Tully — Wed, 13 Mar 2002 04:20:09 GMT

Hi,

Here is another discussion on a similar topic.

http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0xf1d635067c18d6118ff40090279cd0f9,00.html

HTH
-Michael