Quick Beginnings for DB2 Universal Database for UNIX

Step 2. Updating Kernel Configuration Parameters

Depending on your workstation's operating system and its kernel configuration, you may have to update the kernel configuration parameters.

This step is not required on AIX.

Recommended Values for HP-UX Version 10 and Version 11

The values in Table 8 are recommended for the HP-UX kernel configuration parameters.

Table 8. HP-UX Kernel Configuration Parameters (Recommended Values)

Kernel Parameter	Physical Memory
	64MB - 128MB	128MB - 256MB	256MB+
maxuprc maxfiles nproc nflocks ninode nfile msgseg msgmnb msgmax msgtql msgmap msgmni msgssz semmni semmap semmns semmnu shmmax shmseg shmmni	256 256 512 2048 512 (4 * ninode) 8192 65535 (1) 65535 (1) 256 130 128 16 128 130 256 256 67108864 16 300	384 256 768 4096 1024 (4 * ninode) 16384 65535 (1) 65535 (1) 512 258 256 16 256 258 512 512 134217728 (2) 16 300	512 256 1024 8192 2048 (4 * ninode) 32768 65535 (1) 65535 (1) 1024 258 256 16 512 514 1024 1024 268435456 (2) 16 300

Notes:

1. Parameters msgmnb and msgmax must be set to 65535.

2. To maintain the interdependency among kernel parameters, change parameters in the same sequence in which they appear in the preceding table.

3. Parameter shmmax should be set to 134217728 or 90% of the physical memory (in bytes), whichever is higher. For example, if you have 196 MB of physical memory in your system, set shmmax to 184968806 (176*1024*1024).

To continue with the installation on HP-UX systems, proceed to Step 3. Mount the CD-ROM.

Recommended Values for SCO UnixWare 7

The values in Table 9 are recommended for SCO UnixWare 7 kernel configuration parameters.

Table 9. SCO UnixWare 7 Kernel Configuration Parameters (Recommended Values)

Kernel Parameter	Recommended Value
msgmax msgmnb msgssz msgmni shmmax shmmni shmseg semmi	65535 (1) 65535 (1) 524288 256 268435456 300 15 1024

Notes:

1. Parameters msgmax and msgmnb should be set at least to 65535.

2. To maintain the interdependency among kernel parameters, change parameters in the same sequence in which they appear in the preceding table.

3. Parameter shmmax should be set to the suggested value in the above table or 90% of the physical memory (in bytes), whichever is higher. For example, if you have 196 MB of physical memory in your system, set shmmax to 184968806 (176*1024*1024).

To change a value, do the following:

1. Enter the scoadmin command to start the System Administration tool.

2. Double-click on the System folder.

3. Double-click on the System Tuner icon.

4. Click on the drop down box and select the Inter-Process Communication (IPC) Parameters.

5. Select the parameter to be changed and enter the new value.

6. Click on OK when you have finished changing all the parameters.

7. Click on the Yes push button to rebuild the kernel.

8. Reboot the system so that the changes can take effect.

Recommended Values for Solaris

The values in Table 10 are recommended for Solaris kernel configuration parameters.

Table 10. Solaris Kernel Configuration Parameters (Recommended Values)

Kernel Parameter	Physical Memory
	64MB - 128MB	128MB - 256MB	256MB - 512MB	512MB+
msgsys:msginfo_msgmax msgsys:msginfo_msgmnb msgsys:msginfo_msgmap msgsys:msginfo_msgmni msgsys:msginfo_msgssz msgsys:msginfo_msgtql msgsys:msginfo_msgseg shmsys:shminfo_shmmax shmsys:shminfo_shmseg shmsys:shminfo_shmmni semsys:seminfo_semmni semsys:seminfo_semmap semsys:seminfo_semmns semsys:seminfo_semmnu	65535 (1) 65535 (1) 130 128 16 256 8192 67108864 16 300 128 130 256 256	65535 (1) 65535 (1) 258 256 16 512 16384 134217728 (2) 16 300 256 258 512 512	65535 (1) 65535 (1) 258 256 16 1024 32768 268435456 (2) 16 300 512 514 1024 1024	65535 (1) 65535 (1) 258 256 16 1024 32768 536870912 (2) 16 300 1024 1026 2048 2048

Notes:

1. The msgsys:msginfo_msgmnb and msgsys:msginfo_msgmax parameters must be set to 65535.

2. The shmsys:shminfo_shmmax parameters should be set to the suggested value in the above table, or 90% of the physical memory (in bytes), whichever is higher. For example, if you have 196 MB of physical memory in your system, set the shmsys:shminfo_shmmax parameter to 184968806 (176*1024*1024).

To set a kernel parameter, add a line at the end of the /etc/system file as follows:

   set parameter_name = value

For example, to set the value of the msgsys:msginfo_msgmax parameter, add the following line to the end of the /etc/system file:

   set msgsys:msginfo_msgmax = 65535

Sample files for updating the kernel configuration parameters are provided in the /opt/IBMdb2/V5.0/cfg directory. The names for these files are as follows:

• kernel.param.64MB for systems with 64MB-124MB of physical memory
• kernel.param.128MB for systems with 128MB-256MB of physical memory
• kernel.param.256MB for systems with more than 256MB-512MB of physical memory
• kernel.param.512MB for systems with more than 512MB of physical memory

Depending upon the amount of physical memory in your system, append the appropriate kernel configuration parameter file to the /etc/system file. If necessary, change the value of the shmsys:shminfo_shmmax parameter as described in Note 2 above.

After updating the /etc/system file, reboot the system.

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