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kernel recommended parameters

Burhan Koni

kernel recommended parameters

Dear all
I am installing Oracle Applications 11i(11.5.8) on HP-UX (11.11)
I face problems in creating the database that seem to be due to kernel parameters,
I assigned the minimum required values for kernel parameters as they are in installation manual.
can you give the recommended values for the kernel parameters for this installation.

Michael Tully
Honored Contributor

Re: kernel recommended parameters

It all depends on what applications are going to be used in conjunction with oracle. You may wish to review these documents.

Here is what we use on our only oracle server which is being used for data warehouse. These were the recommendations from oracle themselves. You may need to make changes to your buffer cache settings depending on the amount of RAM you have. (dbc_min_pct & dbc_max_pct)

* Configurable Parameters

dump lvol
dbc_max_pct 10
dbc_min_pct 2
ksi_alloc_max (NPROC*8)
max_thread_proc 256
maxdsiz 1073741824
maxdsiz_64bit 2147483648
maxssiz 134217728
maxssiz_64bit 1073741824
maxswapchunks 16384
maxuprc ((NPROC*9)/10)
msgmap (MSGTQL+2)
msgmni NPROC
msgseg 32767
msgtql NPROC
ncallout (NPROC+16)
ncsize ((8*NPROC+2048)+VX_NCSIZE)
nfile (15*NPROC+2048)
nflocks 4096
ninode (8*NPROC+2048)
nkthread (((NPROC*7)/4)+16)
nproc 4096
nstrpty 1024
nstrtel 1024
npty 1024
semmap (SEMMNI+2)
semmni 4096
semmns (SEMMNI*2)
semmnu (NPROC-4)
semvmx 32768
shmmax 4294967295
shmmni 512
shmseg 32
st_ats_enabled 0
vps_ceiling 64
Anyone for a Mutiny ?
Honored Contributor

Re: kernel recommended parameters


Did you install all the patches are required?

Attached the "Installation Update Notes"

hope this helps!

No person was ever honoured for what he received. Honour has been the reward for what he gave (clavin coolidge)
Michael Steele_2
Honored Contributor

Re: kernel recommended parameters

Also depends on size of physical memory. Kernel parameters for 2 gb server will be different for 8 gb server.
Support Fatherhood - Stop Family Law
Honored Contributor

Re: kernel recommended parameters

Attached is an article that define the default kernel parameter settings for the
HP-UX Operating system running Oracle 8.X & 9.X Enterprise Edition. Hope it can help you.
Geoff Wild
Honored Contributor

Re: kernel recommended parameters

Proverbs 3:5,6 Trust in the Lord with all your heart and lean not on your own understanding; in all your ways acknowledge him, and he will make all your paths straight.
Ben Dehner
Trusted Contributor

Re: kernel recommended parameters

In my experience, we never run "an" Oracle database. We usually end up making several copies of a database for development and training. For this case, there is interplay between various Oracle init parameters and resources requires. Here's some to be careful of:

init.ora PROCESSES: this controls how many processes one instance may run. While NPROC and MAXUPROC obviously limit this, each instance will also allocate this many semaphores on startup whether or not it starts this many processes. So SEMMNI and SEMMNS must be set high enough for all instances on the system. Using shared servers so that each client does not need a dedicated process can reduce the amount of processes each instance needs.

kernel NFLOCKS: Each oracle instance acquires a file lock on all of the database files, so the NFLOCKS parameter must be high enough for all datafiles in all running instances on the system.

kernel NFILE: Similar to above, but each Oracle process will open every datafile.
Trust me, I know what I'm doing
Steven E. Protter
Exalted Contributor

Re: kernel recommended parameters

I love what I see in this thread and add this:

A document which is updated every six months by one of HP's top Oracle performance experts.

I'm also attaching my data collection scripts. These are useful for spotting bottlenecks after the applicaiton is up and running.

Further, note that shmmax should never be set to more than 25% of system memory. This is defined as physical memory plus swap.

If you have 2 GB of RAM and 2.0 GB of swap then shmmax will ignore any setting greater than 1 GB anyway.

My current favorite on swap setting for Oracle is as follows:

On smaller primary swap area equal to half of physical memory, priority one.

A second larger swap area equal to 1.5 times physical memory priority 2.

The system really flies when its running light or medium loads and not using the second swap area.

Steven E Protter
Owner of ISN Corporation