Itanium vs PA-Risc for Oracle Databases

[Yogeeraj_1]

hi chris!

may i also suggest that you log an iTar with Oracle on Metalink.

It is true that there is a bug that they have detected. Oracle Database version 10.1.0.2 is also affect by this. but this was reported in january.

You may have found the resolution in the meanwhile.

hope this helps too!

kind regards
yogeeraj

[Zygmunt Krawczyk]

Hi Chris,

if you have configured enaugh swap space, at least 16GB, you can change the kernel parameter swapmem_on to 0 (default is 1). It saves the memory.

What is the date of your OS? If you have OS date prior to Sept 2004, you should upgrade your OS to Sept 2004.

Regards,
Zygmunt

[Chris Fadrowski]

i believe if i just lower the kernel parameter dbc_max_pct from 50 to 20, it will give some of the memory back. As others said, oracle has it's own buffer cache.

[Jean-Luc Oudart]

Hi

20% 16GB => 3.2GB I think this is still too high.
On HPUX11.0 I run between 300 and 400Mb.
I believe on 11i you should set to 800-1000Mb

Regards
Jean-Luc

[Ted Buis]

If you have OnLineJFS, you can eliminate the double buffering done by Oracle and HP-UX. Then there will be even less need for dbc maximum to be set so high. Also, if you are seeing pageouts, then it may be good to turn pseudoswap off if you have enough device swap. However, if you are not doing any page outs then you might as well keep pseudoswap turned on. It really doesn't consume memory, but only locks pages into memory, which elimitates the possibility of those pages being swapped out, thus eliminating the need to have any device swap space reserved for those pages. It does not take some of your memory and turn it into a swap area. It does effectively increase the virtual memory space to the sum of the locked pages plus the device swap space.

[Zygmunt Krawczyk]

In addition to Ted's response, read the doc:

"Best Practices for Oracle on HPUX"
http://h21007.www2.hp.com/dspp/files/unprotected/database/HP3KOracle.ppt

[Tim D Fulford]

Hi

I think every one has done stuff on Oracle.. you should also know HP-UX 11i v1 & v2 uses more memory than HP-UX 11.0.. You'll generally see a large increase in the system memory utilisation from a couple of 100 MB to GB's.

That said, HP say that this is not quite as bad as it may seem although system memory as a % has increased, User memory has decreased... such that there is 10-20% increase in total memory usage..

The above is independant of Oracle and its workings...

Tim