how to change shmmax parameter

[amolik]

I am using oracle 9i on RH linux 7.2. I need to increase the shmmax permanently as it is said in one oof installation documentation. How should I do it. I am getting error "Shared oracle memory realm does not exist'. Is it because of less shared memory.

It is also affecting my auto startup of DB

Amol

[rotem_fo]

Steps required to install Oracle on Linux:
1) log in as root.
2) Create a Software Owner and Group. user=oracle, group=dba.
3) Create the software mount point (ex. /home/oracle).
4) grant permissions to oracle user on the mount point.
5) set up environment variables:
ORACLE_BASE /home/oracle/
ORACLE_HOME /home/oracle/product/8.1.7
LD_LIBRARY_PATH /home/oracle/product/8.1.7/lib:/usr/lib
ORACLE_TERM vt100
PATH /home/oracle/product/8.1.7/bin (followed by whatever else is usually in your PATH)
ORACLE_SID your instance name

6) Set the umask for user oracle to 022.
7) To modify kernel parameters using the /proc file system:
Change to the /proc/sys/kernel directory.
Review the current semaphore parameter values in the sem file using the cat or more utility. For example,
# cat sem
The output will list, in order, the values for the SEMMSL, SEMMNS, SEMOPM and SEMMNI parameters. The following example shows how the output will appear.

250 32000 32 128

In the preceding example, the shared_memory_parameter is either the SHMMAX or SHMMNI parameter. The parameter name must be entered in lowercase letters.

Modify the shared memory parameter using the echo utility. For example, to modify the SHMMAX parameter, enter the following:

# echo 2147483648 > shmmax


log in as oracle user set the SID and startup the instance nomount.

[amolik]

I tried that while installation but it was temporary change. when
I rebbted the machine it again became the same old one

Amol

[sumit]

Hello Amol

Go to /etc system file and change the value for SHMMAX there. This is a permanent change.

Thanks
Sumit

[pando]

look man sysctl

the create sysctl.conf in /etc then create a script in init.d and add SXX and KXX script in your run level directory (normally is 3)