Wednesday, February 01, 2006

Default Kernel Parameters for Sun OS 9.X Database

Metalink Note:187273.1 Type: PROBLEM
Last Revision Date: 21-OCT-2005 Status: PUBLISHED

Solution Description:
This article is to define the default kernel parameter settings for the
Sun OS/Solaris Operating system running Oracle 8.X Enterprise Edition.

Solution Explanation:
In Sun OS the /etc/system file is the kernel parameter file.

The current kernel parameters values can be displayed by using the
'sysdef -i' command.
- Refer to Note 70688.1"Location and Dispay of kernel parameters" for more
information on uderstanding the 'sysdef -i'output.
UNIX Kernel Parameters:
- Defines the maximum number of semaphore sets in the entire system.
- Defines the maximum semaphores on the system. This setting is a
minimum recommended value, for initialinstallation only. The SEMMNS
parameter should be set to the sum of the PROCESSES parameter for each Oracle
database, adding the largest one twice, and then adding an additional 10 for
each database.
- Defines the minimum recommended value, for initial installation only.
SHMMAX 4294967295
- Defines the maximum allowable size of one shared memory segment.
(4 GB = 4294967295)
- Defines the minimum allowable size of a single shared memory segment.
- Defines the maximum number of shared memory segments in the entire system.
- Defines the maximum number of shared memory segments one process can attach.

Note: These are minimum kernel requirements for Oracle9i. If you have previously
tuned your kernel parameters to levels equal to or higher than these values,
continue to use the higher values. A system restart is necessary for kernel
changes to take effect.

* Example of Oracle required parameters:

set shmsys: shminfo_shmseg = 10
set shmsys: shminfo_shmmin = 1
set shmsys: shminfo_shmmni = 100
set semsys: seminfo_semmns = 256
set semsys: seminfo_semmni = 4096
set semsys: seminfo_semmsl = 256
set shmsys: shminfo_shmmax = 4294967295

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