During installation, the installation process checks the values of the shared memory parameters for the required minimum values:
Parameter | Maximum Value | Description |
---|---|---|
semmnu | 2500 | Maximum number of processes that can have undo operations pending on semaphores |
shmmax | 4194304 | Maximum size of a shared memory segment. |
shmmni | 200 | Maximum number of shared memory segments in entire system. |
shmesg | 10 | Maximum number of shared memory segments per process. |
The Teradata Parallel Transporter Base installation does not support formula value for a kernel parameter. If the value for a kernel parameter is less than the required minimum value, the installation will recommend increasing the value to the minimum value.
If any of the above shared memory parameter is less than the minimum value, the Teradata Parallel Transporter Base installation recommends increasing the shared memory parameter to the minimum value using the kmtune command as the root user. Use the following procedure to increase the shared memory parameter to the minimum value.
- To check the shmseg parameter: /usr/sbin/kmtune -q shmseg
- To increase the shmseg parameter to 10: /usr/sbin/kmtune -s shmseg=10
- After the shared memory parameters are changed, rebuild the kernel using the mk_kernel command as the root user: /usr/sbin/mk_kernel
- After rebuilding the kernel, save the current vmunix file: cp /stand/vmunix /stand/vmunix.prev
- Lastly, reboot the machine: /usr/sbin/reboot
-
Then, move the new vmunix file into the /stand directory:
mv /stand/build/vmunix_test /stand/vmunix
If there is a change to the kernel value, the following kernel parameter requires a kernel rebuild and a reboot:
- shmmni
If there is a change to the kernel value, the following kernel parameters do not require a kernel rebuild or a reboot:- shmmax
- shmseg