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
qmatic hard nofile 30000
qmatic soft nofile 30000
qmatic hard nproc 8192
qmatic 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
3. 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.
Kernel semaphores need to be set according to the following command
kernel.sem = SEMMSL SEMMNS SEMOPM SEMMNI
SEMMMSL = 512
SEMOPM = 256
SEMMNI = 256
The SEMMNS is calculated from SEMMSL and SMMNI according to the following calculation
SEMMNS = SEMMSL * SMMNI = 512 * 256 = 131072
4. To make the change permanent, add or change the following line in the file /etc/sysctl.conf: