Sybase recommends that you set the number of available semaphore identifiers to at least 4096. Use this command to display the current values of the semaphore kernel parameters:
cat /proc/sys/kernel/sem
250 32000 32 4096
The four values displayed are:
SEMMSL — Maximum number of semaphores per set
SEMMNS — Maximum number of semaphores system–wide
SEMOPM — Maximum number of operations allowed for one semop call
SEMMNI — Maximum number of semaphore identifiers (sets)
To adjust these values, edit the /etc/sysctl.conf file. Setting values in this file saves them for future reboots. For example, to increase the maximum number of semaphore identifiers to 4096, add the following line:
kernel.sem = 250 32000 32 4096
Make sure that you leave spaces around the equals sign.
To make a change that only lasts until the next reboot, use this command:
echo 250 32000 32 4096 > /proc/sys/kernel/sem
