Manually configured operating system settings

The topics in this section detail general Operating System settings that must be set manually.

Persisting operating system settings

To prevent manually set Operating System settings from reverting on reboot, you should configure some of these settings in the /etc/rc.local script. This script contains commands and scripts that run each time the system is booted.

Vertica uses settings in /etc/rc.local to set the following functionality:

• Disk readahead
• I/O scheduling
• Enabling or disabling transparent hugepages

Editing /etc/rc.local

1. As the root user, open /etc/rc.local:

   # vi /etc/rc.local
   

2. Enter a script or command. For example, to configure transparent hugepages to meet Vertica requirements, enter the following:

   echo never > /sys/kernel/mm/redhat_transparent_hugepage/enabled
   

   Important

   On some Ubuntu/Debian systems, the last line in /etc/rc.local must be exit 0. All additions to /etc/rc.local must precede this line.

3. Save your changes, and close /etc/rc.local.

4. If you use Red Hat 7.0 or CentOS 7.0 or higher, run the following command as root or sudo:

   $ chmod +x /etc/rc.d/rc.local
   

On reboot, the command runs during startup. You can also run the command manually as the root user, if you want it to take effect immediately.

Disabling tuning system service

If you use Red Hat 7.0 or CentOS 7.0 or higher, make sure the tuning system service does not start on when Vertica reboots. Turning off tuning prevents monitoring of your OS and any tuning of your OS based on this monitoring. Tuning also enables THP silently, which can cause issues in other areas such as read ahead.

Run the following command as sudo or root:

$ chkconfig tuned off