The plan is to remove support for CentOS5 / RHEL5. The current installation includes CentOS6.2 (RHEL6.2 compatible). By the time of AMP 7.7 release, the OS included on the installation CD will match the current available CentOS / RHEL release.
You can confirm your current OS release by calling:
# cat /etc/redhat-release
The upgrade steps will be the same as previous OS upgrades:
1. Upgrade AMP to current release
2. Take a backup of AMP
3. Pull the backup to an off server location
4. Reinstall server off current release ISO
5. Copy the backup back onto the server
6. Restore the backup
Here's a link to a past KB article for a previous OS upgrade that goes through the same steps in more details:
http://kb.airwave.com/?sid=50140000000Mf6H