Red Hat Summit8.5. Setting Semaphore Parameters
To determine the values of the four described semaphore parameters, run:
# cat /proc/sys/kernel/sem 250 32000 32 128
cat /proc/sys/kernel/sem 250 32000 32 128
These values represent SEMMSL, SEMMNS, SEMOPM, and SEMMNI.
Alternatively, you can run:
# ipcs -ls
ipcs -ls
All four described semaphore parameters can be changed in the proc file system without reboot:
# echo 250 32000 100 128 > /proc/sys/kernel/sem
echo 250 32000 100 128 > /proc/sys/kernel/sem
Alternatively, you can use sysctl(8) to change it:
sysctl -w kernel.sem="250 32000 100 128"
sysctl -w kernel.sem="250 32000 100 128"
To make the change permanent, add or change the following line in the file
/etc/sysctl.conf. This file is used during the boot process.
echo "kernel.sem=250 32000 100 128" >> /etc/sysctl.conf
echo "kernel.sem=250 32000 100 128" >> /etc/sysctl.conf
