While CentOS and Redhat have a wonderful update facility called Yum, there are some pitfalls to just randomly issuing a ‘yum update’ especially if you have very little experience with the intricacies of your configuration. Like any “techy” geek, I was bored and randomly decided to update my mailserver cluster last night. (yes, I have a cluster.. don’t ask. It’s a redundancy thing even though it’s only for just my personal use).
Normally, I would think ahead, but at 2:32 AM, you don’t think straight and you just issue commands. So.. I did. I issued a yum update and went to sleep. I woke up this morning to find that I hadn’t received any emails and this was a bit troubling. I usually get 200-300 emails a day + spam. (I’m so loved). I hadn’t even received one single spam. Something was up in the state of Denmark.
I definitely figured it was something to do with the update and I decided it would be prudent to check the configs and see what’s up. So here’s where it gets interesting.
Yum decided Postfix needed to be updated, but the rpm wasn’t compiled with MySQL, SASL, and TLS support. So the transport mappings didn’t exist and needless to say, that causes Postfix to die. So back to a manual recompile of Postfix. Anyone that has installed a mailserver knows it’s not a fun task, but I’ve done it enough times in my life that it’s *almost* second nature for me. Just a quick recompile and all is well.
For those of you using CentOS 5.x, the command line is:
make -f Makefile.init makefiles ‘CCARGS=-DHAS_MYSQL -I/usr/include/mysql -DUSE_TLS -I/usr/include -DUSE_SASL_AUTH -DUSE_CYRUS_SASL -I/usr/include/sasl’ ‘AUXLIBS=-L/usr/lib/mysql -lmysqlclient -lz -lm -lssl -lcrypto -L/usr/lib -R/usr/lib -lsasl2’
Then do a Make, then Make Install. Make sure you have the Cyrus-SASL stuff installed, otherwise it won’t work.
So ultimately, take the advice how you want to take it, but think about the effects of issuing a yum update before you do it. If you don’t know what you’re doing or don’t have access to the resources, I don’t suggest you do it unless you can easily get the help you need when things go awry.