Hi, One more helpful doc from Redhat Kbase. http://kbase.redhat.com/faq/FAQ_80_4451.shtm Article ID: 4451 Last update: 12-03-04 Issue: Should I upgrade my existing Red Hat Enterprise Linux system to the next version or should I do a clean install of the later version? Resolution: It is technically possible to do an upgrade of an existing Red Hat Enterprise Linux system to the next version of the operating system in the case where the new operating system is the same class (AS, ES, or WS) as the existing one. In other words, ES 3 can be upgraded to ES 4, AS 2.1 can be upgraded to AS 3, etc. It is definitely *not* recommended to upgrade across two versions, e.g: AS 2.1 to AS 4. There are risks and drawbacks to either approach, as well as potential relative advantages. In the case where an upgrade is performed, there may be complications due to changed configuration file formats in newer versions of component software packages, incompatible versions of libraries, and so on. In some cases, people have upgraded their system for years successfully across many different releases and have not experienced problems. In other cases, people have spent more time reconfiguring the system to fix it after an unsuccessful upgrade than they would have spent on a reinstall. In the case of the reinstall there is the necessity to restore data from backup and reconfigure services and settings. In either case, it is imperative to have a backup of all data in case something goes wrong. Both options require work. How much work is involved in the reinstall depends on the number of services you have configured on the machine and their complexity. Upgrading has the potential of saving time and effort if it is successful. In the case that it is not, it then becomes a question of whether you wish to invest time troubleshooting and fixing any complications or cut your losses and go for the reinstall before you spend too much time. In either case, it is a wise idea to prepare a strategy for doing a reinstall ahead of time, just in case. In the case of a reinstall, you should back everything up, then make a list of services that the machine handles, and copy all the necessary configuration files. Preparing a strategy ahead of time will enable you to work faster and minimize downtime and possible errors. You may also consider executing your planned approach in a test environment first. Nilesh -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subjecthttps://www.redhat.com/mailman/listinfo/redhat-list
