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kernel parameter setting for oracle 9.2.0.2.0

kernel parameter
Occasional Visitor

kernel parameter setting for oracle 9.2.0.2.0

Dear friend ,

We have set the default setting specified in oracle docs.In that shmmax is 4 gb (50% of physical memory.shmmni is 512 and shmseg is 32 .But the processwise mwemory allocation is much more than required .How can this be reduced
6 REPLIES
Steven E. Protter
Exalted Contributor

Re: kernel parameter setting for oracle 9.2.0.2.0

Shalom,

Reducing Oracle memory requirements is like telling the desert to reduce the amount of sand it has.

It won't work.

I would increas shmmni to a minimum of 2048, shmseg to 2048 as well.

You can probably safely reduce shmmax to 25% of physical memory.

You will need to increase maxdsiz_64 maxtsiz_64 and maxssiz_64.

Also needing review:
nproc
maxuprc
nfile

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Steven E Protter
Owner of ISN Corporation
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http://hpuxconsulting.com
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Steven E. Protter
Exalted Contributor

Re: kernel parameter setting for oracle 9.2.0.2.0

Shalom,

Reducing Oracle memory requirements is like telling the desert to reduce the amount of sand it has.

It won't work.

I would increas shmmni to a minimum of 2048, shmseg to 2048 as well.

You can probably safely reduce shmmax to 25% of physical memory.

You will need to increase maxdsiz_64 maxtsiz_64 and maxssiz_64.

Also needing review:
nproc
maxuprc
nfile
dbc_max_pct
dbc_min_pct
dbc is the OS buffer cache. The figures should be low and close to each other for raw device db installs and installs on OS other than 11.23. Some peolple have reported a performance boost with 11.23 and filesystem based databases.
I usually set dbc_max_pct=5
dbc_min_pct=3

Its very expensive in cpu for the system to shift this figure around.

Last
ninodes #should be set reasonably high.
vx_ninodes # should be set to 90% of ninodes

Your milage may vary.

SEP
Steven E Protter
Owner of ISN Corporation
http://isnamerica.com
http://hpuxconsulting.com
Sponsor: http://hpux.ws
Twitter: http://twitter.com/hpuxlinux
Founder http://newdatacloud.com
Oviwan
Honored Contributor

Re: kernel parameter setting for oracle 9.2.0.2.0

Hey

Have a look at the DOC ID 169706.1 in metalink.oracle.com there are specified the hp kernel settings.

Regards
kernel parameter
Occasional Visitor

Re: kernel parameter setting for oracle 9.2.0.2.0

Please can you tell why increasing shmmni and shmseg to 2048 would solve my problem.
kernel parameter
Occasional Visitor

Re: kernel parameter setting for oracle 9.2.0.2.0

I had followed the same article for installing oracle but can you clarify one thing for me that is shmmni = no of processes parameter in oracle or is it related to any other init.ora parameter.

I am sure that shmmni and shmseg parameters tuned to approprate values will resolve the problem but experimenting with them on a production database is really difficuilt and why did you mention both parameters values as 2048 .
cmac
Occasional Advisor

Re: kernel parameter setting for oracle 9.2.0.2.0

Hello all,

Recently, rather than try to untangle the various pre-install requirements I have tended to use the RDA/HCVE tool (see 250262.1) e.g.

./rda.sh -T hcve

This gives a very convenient report specific to the machine I'm working on and covers kernel params, diskspace, memory, OS patches etc so I'd recommend it in a case like this.

However, I have noticed that sometimes it makes recommendations that are slightly different than those documented in the Requirements Quick Ref (see 169706.1) - does anyone with greater experience than myself have any idea why or which I should be more inclined to believe?