Like other operating systems, certain Linux releases depend on timer interrupts for multi tasking. The frequency at which the interrupt occurs is the HZ value. For example, take a Linux box that is configured with a value of "HZ=1000" - this means the OS can raise 1000 interrupts a second. Another kernel option, "divider", is also available. This variable is known to improve throughput by lowering the HZ by the divider value.
In this configuration, the number of interrupts per period changes from the HZ value of 1000 to 100.
Kernel command line parameters are specified in the /etc/lilo.conf or /boot/grub/grub.conf file, depending on the choice of boot loader.
An sample GRUB configuration file entry with the divider option defined looks like:
kernel /vmlinuz-2.6.18 ro root=/dev/hda2 clock=pmtmr divider=10
Reducing the default "HZ=1000" value by using the "divider=10" option is known to cause significant CA SDM internal messaging performance. The CA SDM components are waiting 10 milliseconds(ms) more than what they were prior to using the "divider=10".
This causes performance of normal CA SDM operations to slow down up to 3 times the normal rate.
Please note that the information contained in this document applies to both Primary and Secondary servers that are on a Linux platform.
The "divider=10" option is NOT recommended to be used for a CA SDM server based on Linux.
If this option is already configured, it is recommended that it be removed from the Linux boot configuration files and the server be rebooted for the change to be effective.
For further details, VMware KB: 1006427 covers more details on this topic.
CA highly recommends engaging your Linux System Administrator and VMware Administrator before implementing any change.