Bob wrote: > At Fri, 4 Jun 2010 15:16:05 -0400 CentOS mailing list <centos at centos.org> > wrote: <snip> >> I'm running CentOS 4.8 and have some DVD's for 5.4. I have a lot of >> customized and additional software installed and would like to avoid >> starting over with a scratch install. After the upgrade from the DVD I >> would do a yum upgrade to 5.5. >> >> Is this a workable (and safe) thing to do? What should I look out for? >> > > What I did was carve out fresh /, /usr, and /var file systems out of my > VG (I had enough free space) and did a fresh install, using the > *existing* /boot file system. I thus created a dual boot system: 4.8 AND <snip> > I would recomend *against* trying to do a direct upgrade -- it is too > likely to leave some cruft behind, which could cause all many of > problems later on. It is officially (according to RH, AFAIK) NOT recommended to go up a full release by update. Subreleases are fine, but you want a clean install for a new release (that is, 4.x to 5.x). I recommend what Bob suggested; in fact, I have an article that was published in SysAdmin magazine a few years ago saying just that. (If you want to read the article, it's a link at <http://24.5-cent.us>, and it was called Upgrading Linux). mark