Specifications

Red Hat Enterprise Linux to Oracle Solaris Porting Guide
71
Resource Controls and Runtime Limits
When moving from RHEL to Oracle Solaris 11, one reason an application might face problems is a
difference in the resource limits on the two platforms. The following information can be used to
determine if any changes are required on your system.
Resource Limits on RHEL
On typical RHEL, the ipcs -l command will show the following output. Comments have been
added following the // to show what the parameter names are.
# ipcs -l
------ Shared Memory Limits --------
max number of segments = 4096 // SHMMNI
max seg size (kbytes) = 67108864 // SHMMAX
max total shared memory (kbytes) = 17179869184 // SHMALL
min seg size (bytes) = 1
------ Semaphore Limits --------
max number of arrays = 128 // SEMMNI
max semaphores per array = 250 // SEMMSL
max semaphores system wide = 32000 // SEMMNS
max ops per semop call = 32 // SEMOPM
semaphore max value = 32767
------ Messages: Limits --------
max queues system wide = 15493 // MSGMNI
max size of message (bytes) = 65536 // MSGMAX
default max size of queue (bytes) = 65536 // MSGMNB
To modify these kernel parameters on RHEL, edit the /etc/sysctl.conf file. The following lines
are examples of what should be placed into the file:
kernel.sem=250 256000 32 1024
#Example shmmax for a 64-bit system
kernel.shmmax=1073741824
#Example shmall for 90 percent of 16 GB memory
kernel.shmall=3774873
kernel.msgmax=65535
kernel.msgmnb=65535
You need to run sysctl with the -p parameter, to load in sysctl settings from the default file
/etc/sysctl.conf.
#sysctl –p