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buffer cache question

 
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Luca Rasconi
Frequent Advisor

buffer cache question

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

Thank you

Luca
Luca
4 REPLIES 4
G. Vrijhoeven
Honored Contributor
Solution

Re: buffer cache question

Hi Luca,

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

Gideon
James R. Ferguson
Acclaimed Contributor

Re: buffer cache question

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...
Sridhar Bhaskarla
Honored Contributor

Re: buffer cache question

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
You may be disappointed if you fail, but you are doomed if you don't try
James Murtagh
Honored Contributor

Re: buffer cache question

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.