topic Re: Startup Oracle Instance error in Operating System - HP-UX

Startup Oracle Instance error

uadm26 — Thu, 14 Apr 2005 11:49:33 GMT

Hi,
I have a HP_UX 11.11 system whith 4 GB RAM memory

***********************************************
Kernel :
max_thread_proc 64
nproc 2068
sema 1
semaem 16384
semmap 402
semmni 400
semmns 600
semmnu 30
semmsl 2048
semume 10
semvmx 32767
max_thread_proc 64
maxdsiz 1073741824
maxdsiz_64bit 2147483648
maxssiz 134217728
maxssiz_64bit 1073741824
maxtsiz 0x4000000
maxtsiz_64bit 0x40000000
maxuprc 1280
*****************************************

And I try to create the 8ª instance:
oracle> startup

Report that errors:
ORA-27146: post/wait initialization failed
ORA-27300: OS system dependent operation:semget failed with status: 28
ORA-27301: OS failure message: No space left on device
ORA-27302: failure occurred at: sskgpsemsper
*** 2005-04-14 16:25:48.528

Can you help me? What kernel parameters i need to increase

Re: Startup Oracle Instance error

RAC_1 — Thu, 14 Apr 2005 11:54:59 GMT

Looks like you have a FS that is 100 % full. Check them, particularly /tmp

Anil

Re: Startup Oracle Instance error

A. Clay Stephenson — Thu, 14 Apr 2005 11:55:23 GMT

This is probably because semmni needs to be increased. Do a man 2 semget and see the reasons that segmet() can fail and set errno = ENOSPC (28).

This could also be the result of improper termination of Oracle process so that you have many, many IPCS resources in use. Do an ipcs -a and compare that to your running Oracle instances.

Re: Startup Oracle Instance error

Alex Lavrov. — Thu, 14 Apr 2005 14:03:09 GMT

Before installing oracle, you should consult oracle manuals to see the requirements. They have nice tables with each paramter and it's value.

Can be found on http://www.oracle.com

Re: Startup Oracle Instance error

Julio Yamawaki — Thu, 14 Apr 2005 19:04:22 GMT

Hi,

This error is related to insufficient semaphores.
Please set the value of "semmsl" to a high value say 3000 and rebuilt the kernel.

Re: Startup Oracle Instance error

Indira Aramandla — Thu, 14 Apr 2005 19:52:23 GMT

Hi Joel,

The ORA-27146 means that the system is running out of semaphores. The problem is that there are not enough semaphores to start the instance. The cause for the error is that OS is short of semaphores. You can either decrease the "processes" parameter in the init.ora file, or increase number of semaphores on operating system. The semamphore parameter is called "semmns and semmni.

The first and most simple fix is to modify the init.ora to reduce the number of semaphores or the amount of shared memory Oracle will try to grab at instance startup. If your situation requires that you cannot reduce the appropriate init.ora parameters, you will have to modify the operating system kernel to allow the OS to provide more semaphores or allow larger shared memory segments

With Oracle7:- The number of semaphores required by an instance is equal to the setting the 'processes' parameter in the init.ora for the instance.

With Oracle8, 8i and 9i:- The number of semaphores required by an instance is equal to 2 times the setting of the 'processes' parameter in the init.ora for the instance. Remember that Oracle only momentarily grabs 2 X 'processes' then releases half at instance startup.

Indira A

Re: Startup Oracle Instance error

Yogeeraj_1 — Thu, 14 Apr 2005 23:44:38 GMT

hi,

you need to increase the kernel parameter SEMMNS.

Normally, the Kernel parameter is formula based (SEMMNI * 2). On our system it is currently set to 8192.

Metalink note 115235.1 says:

Set the kernel parameter SEMMNS to double the sum of all of the initSID.ora PROCESSES parameters on the system.

For example, if you have 5 instances with the initSID.ora PROCESSES parameter set to 25, 50, 100, 200, and 250, then set the kernel parameter SEMMNS equal to 1250.

((25 + 50 + 100 + 200 + 250) * 2) = 1250

hope this helps!

regards
yogeeraj

Re: Startup Oracle Instance error

T G Manikandan — Fri, 15 Apr 2005 00:15:49 GMT

The problem is that the semaphores have been completely utilized.

you can check the semaphore usage using

$ipcs -sb |grep

Increase the semaphore kernel parameters and rebuild the kernel to use things up.