Daily Change of "dbc_max_pct" kernal parameter

[Andrew Pollard]

Hi,

We would like to change the buffer cache using the kernel param "dbc_max_pct" twice a day everyday in order to increase performance at night while running a night cycle and then lower it during the day for client access so we are not exceeding any limits?

Has anybody heard of anyone doing this or does anyone know of a reason why this would not be a viable solution?

We would be doing this on a RX7620 running HPUX 11.23 (Itanium). This is a dynamic kernel parameter.

Any thoughts on this would be appreciated.

Thanks

Andrew

[Geoff Wild]

See answers in this recent thread:

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=1002602

Rgds...Geoff

[Victor BERRIDGE]

Hi Andrew
See my reply to Chris...
May I ask what you are running in the evening? in order to understand what gain you have. I have often had to do the opposite...
the trouble with a lot of buffer is that you will have to synchronize to disk some time and at that moment it may seem your box is freezed depending the size (>3GB)


All the best
Victor

[James R. Ferguson]

Hi Andrew:

I suspect that you and Chris are colleagues :-))

See my response here:

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=1002602

Regards!

...JRF...