Sunday, 9 Aug, 2009 CentOS-logo I'm used to Ubuntu and I appreciate its funny sudo apt-get goodness, but for some reasons (spoiler: new job), I got involved with CentOS administration. After learning some yum quirks (if you're used to apt-get and dpkg, believe me, it's easy!), I was given the task to migrate a 32 bit CentOS 4.7 Final install to CentOS 5.3. Some useful yum commands I learned: yum install package yum remove package yum clean all For the migration task, I followed these guidelines: http://wiki.centos.org/HowTos/MigrationGuide/ServerCD_4.4_to_5 I can confirm it worked, except some expected, minor issues, solved by using some sanity. To manually download my packages, I choose a local italian mirror (the garr mirror - ftp://mi.mirror.garr.it/pub/1/centos/5.3/os/i386/CentOS/). I'm not in the mood for a step-by-step howto (too busy ATM, just follow the wiki over there...), but here are some tips, notes and issues I encountered during the process and how I overcame them. Follow the wiki guidelines, at the section: - remove 2.6.9 bits rpm -e kernel-2.6.9-42.EL kernel-devel-2.6.9-42.EL kernel-doc-2.6.9-42.EL make sure you remove ALL 2.6.9x kernel iterations. To know how many kernel iterations you have, just type: rpm -qa | grep kernel then, when launching your rpm -e command, make sure you choose ALL kernel-2.6.9X, kernel-devel-2.6.9x and kernel-doc-2.6.9x instances. Over time, and depending on the server role, kernel revisions may add up (on mine, there were almost 17 instances), so, when I launched the remove command, I (wrongly) thought it was kinda crashy since it took my prompt. I was pretty tempted to stop the process with CTRL+C, but before doing so, I opened another ssh session (BEWARE: make sure you have physical server access), and launched "top". I saw some activity [by the rpm command himself], so I decided to leave it running and I switched doing something else; ~20 min. later I was given my bash prompt back. Another source of concern was when dealing with yum, repos and rpm. I experienced some broken dependencies, some missing libs and some unsatisfied python deps, so I happened to remove the old versions (el4) and installed the new ones.Too bad that, when removing old packages, I ended up on a strange situation: I found myself removing sqlite. Since (probably, not so sure about that), the rpm Db is based on sqlite, I ended up on an inconsistent status, where I couldn't install nor remove anything(!), not with rpm commands neither with yum, so take care when/if playing with a critical system component like sqlite. FYI, i'll post a very useful link, that can help you deal with sqlite and borked rpm db: http://www.raditha.com/blog/archives/001579.html As always (at least, when dealing with linux...), YMMV: I wish you a happy CentOS migration! Please refer to: http://wiki.centos.org/HowTos/MigrationGuide/ServerCD_4.4_to_5 http://www.tocpcs.com/yum-install-centos-5-upgrade-from-centos-44-to-centos-5 http://www.raditha.com/blog/archives/001579.html Rate this post Andrea MatesiSenior Professional Network and Computer Systems Engineer during work hours and father when home. Andrea strives to deliver outstanding customer service and heaps of love towards his family. In this Ad-sponsored space, Andrea shares his quest for "ultimate" IT knowledge, meticulously brought to you in an easy to read format. Share this:LinkedIn Related