centOS upgrade?

[jg196976]

have a server with CentOS 4.8.  Can this version be upgrade to 6.3?

[Matti_Kurkela]

Is the server hardware powerful enough to satisfy the minimum requirements of 6.3?

A direct upgrade from any 4.x release to 6.3 is unlikely to be successful.

The recommended way would be to backup all the data and applications on the system, re-install the OS using the 6.3 version, then restore user accounts, users' home directories and other data. RPM-based applications will need to be reinstalled for sure; it *may* be possible to restore third-party non-RPM application from backup without an actual reinstallation, but you will have to carefully check their functionality with the new OS version.

Note that an upgrade from 4.8 to 6.3 will bring *many* changes to system library versions: to make the old applications work with the new OS version, you may have to install some compat-* RPMs to allow the old applications use the old library APIs.

A multi-step upgrade (4.8 -> 5.x -> 6.3) may be technically possible, but you should note that RedHat won't support upgrades between major versions at all. Not even in RHEL, much less in CentOS.

CentOS wiki:

http://wiki.centos.org/FAQ/General#head-3ac1bdb51f0fecde1f98142cef90e887b1b12a00

27. How do I upgrade from one major release to another?

Upgrades in place are not supported nor recommended by CentOS or TUV. A backup followed by a fresh install is the only recommended upgrade path. See the Migration Guide for more information.