Modifying kernel parameters and user limits (AIX Linux)

IBM® InfoSphere® Information Server requires specific resources for each tier. Modify the kernel parameters and user limits, and restart the computer before you start the installation program.

The kernel parameter and user limit requirements are minimum requirements for InfoSphere Information Server. The optimal value for each parameter might be higher depending on your topology and the operational data load. Additional kernel parameter and user limit changes might be required. When more than one value is provided for your configuration, use the largest minimum value.

All changes must be made by a trained system administrator. Make a backup copy of the kernel parameters and user limits before you modify them. After you modify the kernel parameters and user limits with the suggested values, restart the computer, and then install InfoSphere Information Server.

Minimum kernel parameters

You might need to configure the kernel parameters and user limits for your application server. For more information, refer to the IBM WebSphere® Application Server documentation.

Minimum kernel parameter values for IBM Db2 databases

The minimum metadata repository kernel parameter requirements apply only to Db2® database installations. Before you install Db2 as part of InfoSphere Information Server, ensure that your computer meets the following minimum requirements for kernel parameter for Db2:

  • AIX®: The default kernel parameter values are sufficient.
  • HP-UX: Run the db2osconf utility to have it identify appropriate kernel parameter values for your system. If you have not yet installed the Db2 server, you can get the db2osconf utility from the InfoSphere Information Server installation media in the db2osconf.tar file. Unpack the tar file onto the computer and run it.
  • Linux®: The minimum Linux kernel parameter values are described in the following table:
    Table 1. Minimum Linux kernel parameters and user limits for the metadata repository computer on Db2
    Parameter Value
    MSGMAX 655361
    MSGMNB 655361
    MSGMNI 1024 * <size of RAM in GB>
    RANDOMIZE_VA_SPACE 0
    SEMMNI 256 * <size of RAM in GB>2
    SEMMNS 256000
    SEMMSL 250
    SEMOPM 32
    SHMALL
    • For the default 4096 PAGE_SIZE, use 4294967296
    • For a PAGE_SIZE larger than 4096, divide 17592186044416 by PAGE_SIZE (17592186044416/PAGE_SIZE)
    SHMMAX

    Set this value to be equal to 100% of the physical memory (in bytes) on your computer.
    SHMMNI 256 * <size of RAM in GB>
    1. Required by Db2.

      When the Db2 kernel requirements are different from the InfoSphere Information Server kernel parameter requirements, use the largest minimum value. If you use a different database system for the metadata repository, consult the product documentation for that database system to find information about kernel parameter requirements.

    2. If the kernel command-line parameter ipcmni_extend is not enabled or the system has less than 128 GB of RAM, this value is set to 32768.

When the Db2 kernel requirements are different from the InfoSphere Information Server kernel parameter requirements, use the largest minimum value. If you use a different database system for the metadata repository, consult the product documentation for that database system to find information about kernel parameter requirements.

Minimum AIX kernel parameters

Run the smit or smitty command to modify kernel parameters on AIX. The following table contains the minimum kernel parameters and user limits for the engine and services tiers.

Table 2. Minimum AIX kernel parameters and user limits (engine and services tiers)
Parameter Engine and services tiers
MAXUPROC 4096 or unlimited
NOFILES 10240

Minimum Linux kernel parameters

The following table contains the minimum kernel parameters and user limits for the engine and services tiers.

Table 3. Minimum Linux kernel parameters and user limits (engine and services tiers)
Parameter Engine and services tiers
MSGMAX 8192
MSGMNB 16384
MSGMNI No requirement
SEMMNI 1024
SEMMNS 128000
SEMMSL 250
SEMOPM 32
SHMALL 2511724800

Use the smaller value of 837241600 if the following conditions apply:

  • The computer has only the minimum memory requirement of 4 GB.
  • The computer does not have the metadata repository with Db2 installed.
  • The page size is 4096.
SHMMAX 307200000
SHMMNI 2000
nproc 1000 or unlimited
nofile 10240