Hi, After the previous debacle with PHP and MySQL it has been decided that we think about an upgrade from CentOS 3 to 5, since that would solve our problem, if successful. I tried finding information on how to best attempt this, but thanks to a plethora of contradictory information my head is now spinning with a few rpm (rounds per minute). The situation is as follows: Remote box at our host who offers CentOS 3 as the most up-to-date OS, unless you pay them an unholy amount of money for RHEL or Windows licences. Popping in a CD for an upgrade does not work for us. We can and will have the OS restored to a clean post-install state prior to updating. I have little intimate knowledge with CentOS, RPMs or yum, but general good UNIX experience. I know "live" yum migrations are greatly discouraged, but it seems to work for people. The most detailed instructions I seemed to be able to find are here: http://www.centos.org/modules/newbb/viewtopic.php?topic_id=382 Can anybody confirm this to work, is there anything else that's implied but not spelled out? Another, differing approach seems to be this: http:// levine.sscnet.ucla.edu/general/software/tc1000/rmredhat.htm Any ideas about it? Any hints, or rather detailed steps, would be greatly appreciated. Chrs, Dav
David Christopher Zentgraf wrote:> Hi, > > After the previous debacle with PHP and MySQL it has been decided that > we think about an upgrade from CentOS 3 to 5, since that would solve > our problem, if successful. I tried finding information on how to best > attempt this, but thanks to a plethora of contradictory information my > head is now spinning with a few rpm (rounds per minute). > > The situation is as follows: Remote box at our host who offers CentOS > 3 as the most up-to-date OS, unless you pay them an unholy amount of > money for RHEL or Windows licences. Popping in a CD for an upgrade > does not work for us. We can and will have the OS restored to a clean > post-install state prior to updating. I have little intimate knowledge > with CentOS, RPMs or yum, but general good UNIX experience. I know > "live" yum migrations are greatly discouraged, but it seems to work > for people. > > The most detailed instructions I seemed to be able to find are here: > http://www.centos.org/modules/newbb/viewtopic.php?topic_id=382 > Can anybody confirm this to work, is there anything else that's > implied but not spelled out? > Another, differing approach seems to be this: > http://levine.sscnet.ucla.edu/general/software/tc1000/rmredhat.htm > Any ideas about it? > > Any hints, or rather detailed steps, would be greatly appreciated.I tried it and failed pretty miserably. The box wedged after the "upgrade" and would not boot after being power cycled. I didn't really do a detailed "WTF" analysis afterwards since we do have physical access to the machine. So I had someone pop in a CentOS 5 DVD and pave over the system and walked them through which options to check during the install. Once it was back up and reachable from the net, I selectively restored bits I needed from the backup I did before the experiment. This was a CentOS 3 machine on a pretty vanilla dual Opteron box and was patched "up to the minute" as of the day the upgrade was attempted. If you manage to sort things out, I'll be curious to know how you did it. Best,
David Christopher Zentgraf wrote:> Hi, > > After the previous debacle with PHP and MySQL it has been decided that > we think about an upgrade from CentOS 3 to 5, since that would solve our > problem, if successful. I tried finding information on how to best > attempt this, but thanks to a plethora of contradictory information my > head is now spinning with a few rpm (rounds per minute). > > The situation is as follows: Remote box at our host who offers CentOS 3 > as the most up-to-date OS, unless you pay them an unholy amount of money > for RHEL or Windows licences. Popping in a CD for an upgrade does not > work for us. We can and will have the OS restored to a clean > post-install state prior to updating. I have little intimate knowledge > with CentOS, RPMs or yum, but general good UNIX experience. I know > "live" yum migrations are greatly discouraged, but it seems to work for > people. > > The most detailed instructions I seemed to be able to find are here: > http://www.centos.org/modules/newbb/viewtopic.php?topic_id=382 > Can anybody confirm this to work, is there anything else that's implied > but not spelled out? > Another, differing approach seems to be this: > http://levine.sscnet.ucla.edu/general/software/tc1000/rmredhat.htm > Any ideas about it? > > Any hints, or rather detailed steps, would be greatly appreciated.You say that the Box will be restored to ac "clean post install state" ... does that mean you do not have any data that you need on there? If you will not have any "data" on there that is important or needs to be preserved then there is no need to UPGRADE the install at all ... you can do a remote VNC install of CentOS-5 via http. Here is an example: <http://www.karan.org/blog/index.php/2005/06/15/upgrading_to_centos4_over_a_remote_vnc_c> For CentOS-5, this option needs adding to the "kernel" line: noipv6 All Anaconda options can be viewed here: http://fedoraproject.org/wiki/Anaconda/Options Thanks, Johnny Hughes -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 252 bytes Desc: OpenPGP digital signature URL: <http://lists.centos.org/pipermail/centos/attachments/20071025/812e7b5f/attachment-0004.sig>
On Thu, Oct 25, 2007 at 05:32:46PM +0900, David Christopher Zentgraf wrote:> The situation is as follows: Remote box at our host who offers CentOS > 3 as the most up-to-date OS, unless you pay them an unholy amount of > money for RHEL or Windows licences. Popping in a CD for an upgrade > does not work for us. We can and will have the OS restored to a clean > post-install state prior to updating. I have little intimate > knowledge with CentOS, RPMs or yum, but general good UNIX experience. > I know "live" yum migrations are greatly discouraged, but it seems to > work for people.It _can_ work, although it might be a little messy. I recently did a FC3 -> CentOS 5 "upgrade" remotely. It was a hassle. Lotsa RPM's don't play nice, and I had ended up trying to go from FC3 -> CentOS 4 the first time around which obviously didn't work out too well so I introduced some other issues by doing that (FC3 was the base for RHEL4 / CentOS 4, so there are some versioning conflicts). Ultimately I think I upgraded the mess I made with that to FC4 and then to CentOS 5. :) My best recommendation if you have no other choice is to remove as many RPM's as you can -- get it as bare bones as possible. Point your Yum repo at the new repository and do a yum upgrade and see what errors you come across. Try and resolve, or just remove the offending RPM's. In some cases I would either manually install an RPM to fix a dependancy or rebuilt from an SRPM to add a Provides line at least to get the upgrade going. I didn't keep notes unfortunately on my process, but it did take quite a while. :) Eventually it did work however. YMMV... maybe your colo would set you up with an IP KVM or something temoprarily and you could do your own install? And perhaps a CentOS 3 -> CentOS 4 -> CentOS 5 upgrade would work better. I'm sure others will comment.