Migration questions / Looking for advice

[peter@mxtoolbox.com]

I have two 4.5.6 NE machines setup right now with LDAP replication and a good number of users.

I want to eventually get to running version 5. I am thinking about bringing up a new separate box running version 5.0.2 and want to know two things.

1) Can you add a 5.0.2 server to join LDAP replication with 4.5.x boxes? I don't think so but wanted to confirm.

2) If you cannot share LDAP with 4.5.x, how can I migrate boxes from an completely separate 4.5.x box to a 5.0.2 box? If they were connected with LDAP I could use zmmailboxmove, what other solutions do I have without that?

I'm scared of migrating the 4.5.6 box in place because the "worst case" scenario has me reinstalling and doing a restore from backups. The problem is that the backups are sitting at like 200GB right now and that means my service is offline for 12+ hours.

Also if I do the upgrade in place, I have to bring down both servers and do the upgrade simultaneously, correct?

[gmsmith]

Peter,

I think you best option is an in place upgrade. We went through something similar recently. What we did was did a hot rsync of the /opt/zimbra director minus the backups dir to a remote drive. Then the day of the upgrade, stopped ZCS, did another rsync, which took significantly less time, then proceeded with the upgrade.

In your case, I would go to 4.5.11 then 5.02 (or maybe 5.03 depending on timing) all in one sitting. 4.5.11 addresses some stuff related ldap replicas, and be sure to read the release notes/wiki entry on it.

[peter@mxtoolbox.com]

Thanks, the rsync idea sounds like an awesome idea. I hadn't thought about that it for this, but I've done that before and it worked awesome.

Thanks!

[gmsmith]

No problem...

Here is what we used:

rsync -avr /path/to/source /path/to/destination/

[mmorse]

I have two 4.5.6 NE machines setup right now with LDAP replication and a good number of users.

Good plan - just don't forget about LDAP Replicas 4.5.x to 5.0.x - Zimbra :: Wiki

[peter@mxtoolbox.com]

Okay, so I attempted to do a dry run on a virtual machine and discovered that rsyncing the /opt/zimbra directory is not going to work. I have 160GB and 1.3 million files there, so the rsync process ran 18.3 hours. I could just do a full restore in that amount of time (13 hours on avg for a full restore).

Does anybody know for sure that the /store and /index directories are NOT touched during the upgrade procedure? I could probably do that rysnc in a reasonable amount of time.

Thanks,
Peter

[gmsmith]

The beauty of rsync, is that once it finishes its first rsync, it just does changes. So let it run for that long (which does sound a little long), but when you are ready to do the upgrade it will take a very small fraction of that time to finish up.

[peter@mxtoolbox.com]

This feature I know (and love).

But the USB disk is there in case the upgrade goes kabloey (sp?). What I'm saying is that if I spend time doing the upgrade and as a last resort I have to rely on the rysnc BACK from the USB disk, then I'm looking at 18 hours to copy the files back.

By excluding the store and index I'm looking at 28k files instead of 1.3m. I just wanna know if I can count on store and index not to get clobbered during the upgrade scripts. I don't think they will, but I'm not willing to bet the farm on it on my gut.

[gmsmith]

Can't answer your store question, but in my experience the sync back goes a lot quicker, since it is writing to multiple discs with a raid card. Maybe it is my imagination, but i have seen a sync back complete in half the time.

[Klug]

Why not rsyncing directly to the new server (as I read in the first post you were going for a new box) ?

Using the blog method with little change should work :
. forget step one (hey, this guy is nuts, he says to forget backup)
. start with step 2, meet your new server
. then step 3, dummy install on new server (same Zimbra version as current Zimbra server) and then remove it
. then step 4 but direct rsync (from "old" server to "new" one, not using the "external HD"), then stop the "old" server, then install Zimbra on new server
. then step 5, upgrade Zimbra on new server

You can do step 4 in several steps : an initial long rsync then when you really want to upgrade, a new quick rsync.

And if you mess up your Zimbra upgrade on new server (step 5), you can bring old server back up...
And start everything over later.

All you need is an MTA able to spool incoming mails while you upgrade.
And another box (obviously) but if in the end you stay with 2 servers, you'll can reuse (for stg else) one of the "old" servers.