转贴oracle:Configuring Kernel Parameters

2.6 Configuring Kernel Parameters

Note:

The kernel parameter and shell limit values shown in the following section are recommended values only. For production database systems, Oracle recommends that you tune these values to optimize the performance of the system. Refer to your operating system documentation for more information about tuning kernel parameters.

Verify that the kernel parameters shown in the following table are set to values greater than or equal to the recommended value shown on Solaris 8 and Solaris 9 operating systems. The procedure following the table describes how to verify and set the values.

Parameter Recommended Value
noexec_user_stack 1
semsys:seminfo_semmni 100
semsys:seminfo_semmns 1024
semsys:seminfo_semmsl 256
semsys:seminfo_semvmx 32767
shmsys:shminfo_shmmax 4294967295
shmsys:shminfo_shmmin 1
shmsys:shminfo_shmmni 100
shmsys:shminfo_shmseg 10

 

Note:

The following parameters are obsolete in Solaris 9:
shmsys:shminfo_shmmin

shmsys:shminfo_shmseg
 

On Solaris 10, verify that the kernel parameters shown in the following table are set to values greater than or equal to the recommended value shown. The table aslo contains the resource controls that replace the /etc/system file for a specific kernel parameter.

Note:

In Solaris 10, you are not required to make changes to the /etc/system file to implement the System V TPC. Solaris 10 uses the resource control facility for its implementation.

Parameter Replaced by Resource Control Recommended Value
noexec_user_stack NA 1
semsys:seminfo_semmni project.max-sem-ids 100
semsys:seminfo_semmsl process.max-sem-nsems 256
shmsys:shminfo_shmmax project.max-shm-memory 4294967295
shmsys:shminfo_shmmni project.max-shm-ids 100

On Solaris 8 and Solaris 9 operating systems, use the following procedure to view the current value specified for these kernel parameters, and to change them if necessary:

To view the current values of these parameters, enter the following commands:

# grep noexec_user_stack /etc/system
# /usr/sbin/sysdef | grep SEM
# /usr/sbin/sysdef | grep SHM

If you must change any of the current values, then:

Create a backup copy of the /etc/system file, for example:

# cp /etc/system /etc/system.orig

Open the /etc/system file in any text editor and, if necessary, add lines similar to the following (edit the lines if the file already contains them):

set noexec_user_stack=1
set semsys:seminfo_semmni=100
set semsys:seminfo_semmns=1024
set semsys:seminfo_semmsl=256
set semsys:seminfo_semvmx=32767
set shmsys:shminfo_shmmax=4294967295
set shmsys:shminfo_shmmin=1
set shmsys:shminfo_shmmni=100
set shmsys:shminfo_shmseg=10

Enter the following command to restart the system:

# /usr/sbin/reboot

When the system restarts, log in and switch user to root.

On Solaris 10, use the following procedure to view the current value specified for resource controls, and to change them if necessary:

To view the current values of the resource control, enter the following commands:

# id -p // to verify the project id
uid=0(root) gid=0(root) projid=1 (user.root)
# prctl -n project.max-shm-memory -i project user.root
# prctl -n project.max-sem-ids -i project user.root

If you must change any of the current values, then:

To modify the value of max-shm-memory to 6 GB:

# prctl -n project.max-shm-memory -v 6gb -r -i project user.root

To modify the value of max-sem-ids to 256:

# prctl -n project.max-sem-ids -v 256 -r -i project user.root