A major event for one of the most popular server distros is taking place today. As of March 31st, 2017, CentOS 5 is EOL (end of life) and will no longer receive further security updates or support.

If you’re still using CentOS 5 in any of your systems, we highly recommend you plan for upgrading to CentOS 6 or 7 as soon as possible. Otherwise, you run an increased risk of being compromised.

The safest migration method, as recommended by the CentOS community, is the following:

• Take and test a full backup of the old system.
• Bring up a second system with CentOS-6 either on new hardware, or on an alternate set of disks/partitions.
• Port over applications, data, and settings for users and the system from CentOS-5 to CentOS-6 looking for file and application syntax and operational differences.
• Look for /etc/*.rpm* configuration files backups left over from updates and compare old to current versions, adapting as required.
• Take down old system and move to new system.

We recommend you read this CentOS forum thread for further discussion on the nuances of moving from version 5 to 6.