HP-UX Kernel configuration

[George Nikoloudis_1]

Hi,

I have a Superdome with Oracle Database 8i. I am looking for some information concerning the Kernel configuration in order to take advantage of the Power of Superdome.

Can you help?

Thanks
eorge

[G. Vrijhoeven]

Hi eorge,

I found a whitepaper for the rp8400 and oracle 8i. It might interest you. Kernel paramater settings are provided.

http://www.hp.com/products1/servers/rackoptimized/rp8400/rp8400infolib/biz_intelligence_verification.pdf

HTH,

Gideon

[Stefan Farrelly]

Heres the configurable parameters section from the kernel (/stand/system) that we use on all our superdomes running oracle8i - weve found these to be the optimim setting;

STRMSGSZ 65535
maxswapchunks 4096
maxdsiz 0X7B03A000
maxdsiz_64bit 0X7B03A000
maxssiz 401604608
maxssiz_64bit 0X40000000
maxtsiz 0X40000000
maxtsiz_64bit 0X7B03A000
npty 200
nstrpty 200
semmni 7000
semmns 14000
semmnu 3500
semume 64
semvmx 32768
shmmax 2147483648
shmmni 1000
nfile 16000
nflocks 2048
ninode 10000
vx_ninode 9000
maxuprc 500
maxusers 500
dbc_max_pct 10
dbc_min_pct 2
max_fcp_reqs 512
msgmni 500
msgtql 400
nproc 1000
nstrtel 100
ncallout 4096
default_disk_ir 1
fs_async 0
dnlc_hash_locks 512
max_thread_proc 1100
page_text_to_local 1

[Sridhar Bhaskarla]

Hi,

There aren't any parameters that can dramatically improve the performance.

timeslice is one parameter that you would need to have a look at. Having it lower than the default of 10 will increase CPU context switches.

Buffer cache dynamic parameters (dbc_max_pct and dbc_min_pct) are worth considering. By default HP will make max_pct as 50% and it can be a over kill of memory as well causing mini-hangs during buffer flushes. However you don't want it too small that will reduce the advantage of caching. Having it around 700MB can help you.

There are advanced JFS options available like mincache and convosync that can bypass the system's buffer cache. Well, I tried them and I didn't see any improvement if not the degradation. May be your environment can take advantage of it. You can leave your indexes and archivelogs buffered though.

-Sri

[Steven E. Protter · Accepted solution]

A good Oracle Kernel is going to use that superdome quite nicely.

I recommend you be liberal with shared memory and go way above the oracle minimums from http://metalink.oracle.com

You should also load test the database and collect performance data with the script I'm attaching.

The bottom line is no matter what cookbook you find, you are going to have to adapt to your box after Oracle is running on it.

Also, Oracle 8i is at the end of its support life cycle. You may want to consider 9i.


SEP

[Hemanth Gurunath Basrur]

Hello George,

Refer to the "Tunable Kernel Parameters" manual for more information.

http://docs.hp.com/cgi-bin/fsearch/framedisplay?top=/hpux/onlinedocs/TKP-90203/TKP-90203_top.html&con=/hpux/onlinedocs/TKP-90203/00/00/7-con.html&toc=/hpux/onlinedocs/TKP-90203/00/00/7-toc.html&searchterms=parameters%7ckernel&queryid=20040131-082449

HTH.

Regards,
Hemanth