topic Re: buffer cache question in Operating System - HP-UX

buffer cache question

Luca Rasconi — Tue, 04 Mar 2003 15:54:57 GMT

Hi all,
how can i know the amount of buffer cache used in the system?

Thank you

Luca

Re: buffer cache question

G. Vrijhoeven — Tue, 04 Mar 2003 15:58:40 GMT

Hi Luca,

You can check it with glance or gpm if you have that installed.

Gideon

Re: buffer cache question

James R. Ferguson — Tue, 04 Mar 2003 16:00:08 GMT

Hi:

You can run 'glance' for a dynamic view. Toggle the 'm'emory metrics screen by typing 'm'.

Use 'kmtune -l' to see your kernel parameters. For buffer cache, you should look at 'dbc_min_pct', 'dbc_max_pct', 'nbuf' and 'bufpages'. The latter two parameters should be set to zero to enable the 'dbc_min_pct' and 'dbc_max_pct' dynamic buffer cache.

Regards!

...JRF...

Re: buffer cache question

Sridhar Bhaskarla — Tue, 04 Mar 2003 16:17:13 GMT

Hi Luca,

If you don't have glance installed on your box, you can use kmeminfo to get this information.

You will need to have Q4 (patched) installed on the box.

Run

#/usr/contrib/Q4/bin/kmeminfo

Look for Buffer Cache section and multiply with 4096.

-Sri

Re: buffer cache question

James Murtagh — Tue, 04 Mar 2003 16:28:53 GMT

Hi Luca,

In addition to the above you can run the following command:

# echo bufpages/D|adb -k /stand/vmunix /dev/kmem

Again, this is the amount in pages so multiply by 4096 for the amount in bytes.

Regards,

James.