Upgrade questions - what to do first

[Brian@MCC]

I am currently running Redhat ES 4.5 64 bit server with ZCS Network 4.5.9 64bit for Redhat 4.5.

I would like to upgrade my server to Redhat 5 running the latest ZCS 5.0.1 64 bit.

Which to upgrade first? Do I need to upgrade my ZCS to the latest version for RH 4.5? Or, do I upgrade my RH to 5 then upgrade my ZCS?

I do not want to mess this up! Thanks.

[mmorse]

This guide explains how:/blog/archives/2007/10/moving_zcs_to_another_server.html
-For the switch you have to use the exact same zimbra version
-UID's are often important
It's up to you which you do first, but keep in mind it's harder to downgrade zimbra - so if there's any reason you need to go back to 4.5.x you can't. Thus I would switch platforms first, then upgrade once I was sure all was working well.
You could always throw on 4.5.10 as your first upgrade if you want.
Please don't forget to make plenty of backups!

[Brian@MCC]

Would the 4.5.10 for RH5 version work on a RH4.5?

One thing I've noticed in my test installs is that ZCS builds for RH4.5 do not work well on RH5. Or, (something I've never tried) would installing ZCS for RH5 on a RH4.5 box and then upgrading to RH5 fix those problems? I don't remember exactly what they were, it's been awhile but services weren't starting on the RH5 box with ZCS 4.x built for RH4.5.

[mmorse]

Ya don't do that, there are binaries for 4.5.x & 5.0.x on each platform respectively.

So going to 4.5.10 first is entirely optional, you don't have to do versions incrementally - but if you wanted to your process would look something like:
-make a full backup of 4.5.9
-upgrade existing box to 4.5.10 using same platform binary
-test 4.5.10 for a day
-platform switch (in essence the blog article is a backup in itself but you can always make another as you wish)
-test 4.5.10 on new platform for a day
-full backup of 4.5.10
-upgrade to 5.0.1
-test 5.0.1
-make a fresh backup (because now all your old backups are invalid unless you reinstall 4.5.10/.9)

Sorry if that's a lot of storage space used in that method with 30k users...just showing you the safest route (not going to 4.5.10 would eliminate one of those backups OR if you got on .10 comfortable for a week & decided to remove the .9 backups etc).

Of course vary 'test for a day' for however long you feel comfortable/can have downtime to do the upgrades.
The more you tell us about your setup/IT procedures the more we can pin stuff down for you.
-Are your existing boxes getting RHEL 5 or are these new boxes?
-Do you want this all done in one night - be sure to allow yourself a 'rollback' time window.
-Obviously some people don't have space/can't afford to store more than one full backup at a time, happens more than you think.
-I'm just grasping at variables for ya

If I was doing this in one night on my systems, a backup before the platform switch & another before the ZCS upgrade would be in order at the minimum in case of any 'gotcha's" in the morning. Plus, if the platform switch worked but new zimbra didn't I could save some retry/restore time by getting at least half way...

Alternatively, if the platform switch can be put off but the ZCS upgrade can't; then obviously upgrade zimbra first, make sure you're running fine on 5.0.1 for a few days, make backups, then switch platforms.

If I've done nothing more than scare you into making backups with my above ramblings then my job is done
If I only had a $ for every time I've heard the phrase: "well I didn't make a backup..." then I'd be ___(fill in some nonsensical aspiration)___.

http://www.zimbra.com/forums/announc...r-profile.html

[Brian@MCC]

Backups aren't really a huge problem, other than eating up tapes like nobody's business. My biggest concern is after upgrading 4.5.10 on RH 4.5 then upgrading the platform what problems can I expect? The reason I ask is I may have to do this during a couple of quarter breaks depending on how long everything takes.

Roughly how long does an upgrade take with upwards of 22K mailboxes? I'm running my linux "/" partition at 926.41 GB with 805.60 GB free on a dual 2.73ghz (or something like that) dual core with 8 gig of ram.

[mmorse]

Here's a thread that might interest you: Time Required for 5.0 Upgrade