our server still runs 5.0.9 which is pretty out of date. Sooner or later, I'll have to upgrade. Also, I am affected by the ClamAV version thing (I disabled AV now). To cut it short, it's about time.
I have to admit, I'm a bit afraid of upgrading. As far as I've read, it's not much more than downloading the most recent version, unpacking it and running ./install.sh - and then hopefully everything works fine. Is it really that easy?
First step - backups. I'd like to know what'd be the best way to backup so if something terribly fails I could instantly restore.
What I am currently doing is have the server backup itself with the default schedule (full backup weekly, incremental daily, remove after 1 month) to /opt/zimbra/backup. Nightly, I rsync that folder to our backup server. But what if something really goes terribly wrong? Safest way to recover would be installing the OS from scratch, install 5.0.9, run yum update and import the accounts from the backups, right?
That'd take very long and I am wondering if there isn't a better, smarter way.
Disk/partition images would be an option, I guess, but I'd have to live with quite some downtime. For example, I could boot the server from a SystemRescueCD and use partimage or such to make images to an external hard disk or a network share. In this case, restoring would be as easy, but I'd have to live with some downtime.
What would you do, what's the best backup for a "quick and easy" disaster recovery (as far as that is possible)?
Next, the upgrade - is there anything worth mentioning that I should pay attention to? Any traps people often step into? I'm grateful for every piece of advice.
Last question - I've read here that a new 5.x version as well as a new 6.x version shipped - I assume this means that 5 is still continued? If so, which version should I choose? Is version 6 a "new product" that my v5 license does not cover? This confuses me a bit.
Thank you in advance!