Many system administrators, particularly those managing large database servers, have had difficulty tuning shared memory and semaphore parameters in /etc/system. Often, these difficulties are experienced before starting an application instance. The Solaris[TM] 10 Operating System addresses this issue by integrating the System V IPC tunables into a powerful and flexible framework for easy administration.
If you want to know, how many semaphores are using on the Solaris system,use below command to check it.
If you want to know, how many semaphores are using on the Solaris system,use below command to check it.
#ipcs -s
IPC status from as of Thu Jul 26 13:32:36 EDT 2012
T ID KEY MODE OWNER GROUP
Semaphores:
s 83886476 0x56bd14 --ra-ra-ra- test sap
s 100663690 0x6f471c --ra-ra-ra- gnmsf sap
s 100663689 0x6f3970 --ra-ra-ra- tm052 sap
s 100663688 0x6f3330 --ra-ra-ra- xcdfm sap
s 83886977 0x3bfade --ra-r----- tm051 sap
s 83886976 0x3c4900 --ra-r----- tm051 sap
s 83886932 0x2dca0e --ra-r----- tm056 sap
s 83886931 0x2e182e --ra-r----- tm056 sap
s 83886930 0x2dca0f --ra-r----- tm056 sap
s 83886917 0x33bd7f --ra-r----- tm056 sap
s 67109695 0x2e182f --ra-r----- tm056 sap
s 100664108 0xa173b01a --ra------- root root
You can simple use ipcs -a |wc -l to see the total count.
# ipcs -a |wc -l
15
you have to subtract first three lines from that out. 15-3=12.
If you want to see including NSEMS value ,you can use below command,
#ipcs -sb
IPC status from as of Thu Jul 26 13:32:36 EDT 2012
T ID KEY MODE OWNER GROUP NSEMS
Semaphores:
s 83886476 0x56bd14 --ra-ra-ra- test sap 1
s 100663690 0x6f471c --ra-ra-ra- gnmsf sap 1
s 100663689 0x6f3970 --ra-ra-ra- tm052 sap 1
s 100663688 0x6f3330 --ra-ra-ra- xcdfm sap 1
s 83886977 0x3bfade --ra-r----- tm051 sap 20
s 83886976 0x3c4900 --ra-r----- tm051 sap 20
s 83886932 0x2dca0e --ra-r----- tm056 sap 20
s 83886931 0x2e182e --ra-r----- tm056 sap 20
s 83886930 0x2dca0f --ra-r----- tm056 sap 20
s 83886917 0x33bd7f --ra-r----- tm056 sap 20
s 67109695 0x2e182f --ra-r----- tm056 sap 20
s 100664108 0xa173b01a --ra------- root root 1
# id -p
uid=0(root) gid=0(root) projid=1(user.root)
Current project is user.root . you can find the same in /etc/project file as well.
[ QA - Root:~ # ] cat /etc/project
system:0::::
user.root:1::::
To check the maximum system value for above mentioned project user.root,
# prctl -n process.max-sem-nsems $$
process: 26108: bash
NAME PRIVILEGE VALUE FLAG ACTION RECIPIENT
process.max-sem-nsems
privileged 512 - deny
system 32.8K max deny
#
Current limit for root user is 512 semaphores .
System Limit is 32.8K
We can modify the values using prctl on the fly.Please refer Resource-management for more information
Thank you for reading this article.Please leave a comment if you have any doubt ,i will get back to you as soon as possible.