Installation Note - CentOS
Before running the Orchestra installer on CentOS there are a few steps you need to go through:
1. Settings for “max user processes” and setting for “max open files”.
We recommend increasing the setting of “max user processes” to 2048 and increasing “max open files” by 30000.
If running other processes on the Orchestra server, these settings might have to be increased further.
Current max user processes limit can be verified by running:
ulimit -u
Current max open files limit can be verified by running:
ulimit -n
We suggest increasing this by adding the following lines to the end of the file
/etc/security/limits.conf.
In this example “orchestra” is the username of the user that will run the installer and the user that Orchestra will run as.
After modifying this file, the system will require a reboot. Verify the settings again after reboot.
# Limits for orchestra installer
orchestra hard nofile 30000
orchestra soft nofile 30000
orchestra hard nproc 8192
orchestra soft nproc 8192
2. Make sure host name is resolvable.
Orchestra installer requires that host name of the machine is resolvable. You can check host name in the file /etc/sysconfig/network.
You can verify that it is possible to resolve this by running:
ping HOSTNAME
If you get a response “ping: unknown host HOSTNAME” you will have to add the HOSTNAME to the file /etc/hosts.
Add the following line to the end of the hosts file:
127.0.0.1 HOSTNAME
When running the installation using the embedded PostgreSQL database, a default Linux system sometimes has too low memory settings. The PostgreSQL process requires larger settings for shared memory, compared to the usual default of 32 MB.
3. Verify the current memory setting (ignore the lines beginning with “error: permission denied”):
sysctl -A|grep shmmax
This should output a line like this:
kernel.shmmax = 33554432
4. If the value is less than 268435456 (256MB), perform the following action to set the value:
sudo sysctl -w kernel.shmmax=268435456
5. Edit the file /etc/sysctl.conf and add this line to the end of it (to make the change apply when the machine is restarted):
kernel.shmmax = 268435456
6. Update the Semaphore parameters. First, verify the Semaphore parameters, by running the command:
lpcs -ls
This should output something like:
max number of arrays = 128
max semaphores per array = 250
max semaphores system wide = 32000
max ops per semap call = 32
semaphore max value = 32767
Update the parameters, by running the command:
echo 512 32000 256 256 > /proc/sys/kernel/sem
Finally, verify the parameters by running the command:
lpcs -ls
7. To make the change permanent, add or change the following line in the file /etc/sysctl.conf:
echo “kernel.sem=512 32000 256 256”>>/etc/sysctl.conf