My Successful (CentOS/4.5.6) to (UBUNTU/5.0.4) upgrade

[dwill]

How I migrated from
ZCS 4.5.6 NE running on CentOS 4
to
ZCS 5.0.4 NE running on Ubuntu 6.06.1 LTS Server.

I read through several posts and even sought advice from others who had made similar migrations. All of the upgrade paths discussed seemed to focus on getting the existing version working on the new hardware / platform then performing the upgrade to the latest version. I REALLY wanted a clean install so I chose to do my upgrade this way:

Bring ZCS up to the latest version on the existing hardware & OS.

Do a clean install of the latest ZCS on the new hardware & OS

Then perform a full backup on the old machine & restore on the new.

My goal was to have a machine running the latest ZCS on a supported OS.

Here we go:
upgrade 4.5.6 to 4.5.11 (following the advice not to try to make the jump all the way up to 5.0.4 in one jump)

We use 3Ware raid controllers which make fallback really easy if something should go wrong. Before performing each upgrade, I simply break the mirror and run the upgrade on one drive. If success, re-establish the mirror and sync back up to new install. If problems arise, remove the fouled upgrade and turn the mirror back on reverting to previous state. Comes in really handy

upgrade 4.5.11 to 5.0.4.

Both version upgrades went smooth and our “old” box was now running the latest version of ZCS on CentOS.

Step 3 – The new machine is a clean install of Ubuntu 6.0.6 Server.
The machine was a complete default install with a temporary internal static IP and temporary hostname, since I wanted to Rsync directly to this box on the same network as the running mail server.

We use a split DNS which required:

Sudo apt-get install bind9

If desired, I can post details of bind config

Once DNS was configured, I disconnected from the network and duplicated the settings of the existing mail server.
On existing mail server : zmcontrol stop
Disconnect from network

Connect new server and test DNS – I wanted to test this because I know it must work for the install to function properly. Once tested, I reverted back to a different IP and hostname, and brought the “old” server back online.

On the new server – using the ZCS NE for 5.0.4 / Ubuntu 6.06
Sudo ./install.sh –s
Software only install, once complete delete the contents
rm –rf /opt/zimbra

Stop mail services and rsync /opt/zimbra to new machine
From the new box, I started to Rsync from the existing mail server:

Rsync –avz <ipaddress>:/opt/zimbra /opt/zimbra

-- Here’s where I had to change my plans a bit --
After 4 hours, I stopped the process so that I could enable mail services again.
I didn’t plan on rsync taking so long.
Investigation revealed a little cleanup was in order, as we had suffered from some of the earlier bugs which had been fixed in newer versions:
My /opt/zimbra/log/zmmtaconfig was at 15 Gig
We had several previous version of ZCS stored in the /opt/zimbra/backup folder from previous upgrades as well as previous versions of supporting applications. Additionally, I didn’t feel it was necessary to rsync all of the backups, so I moved all but the most recent full and incrementals out of the zimbra directory.

My rsync size was reduced by 40 gig 

Still not wanting to have mail services down for too long, I stopped zimbra on the old machine long enough to make a local copy of /opt/zimbra then resumed mail service.

Finally, start the rsync again without needing mail services stopped.
While this was going on, I decided it would be nice to use the administration console in the server room, so I installed the desktop on the new machine.

Sudo apt-get install ubuntu-desktop

24 hours later… (I went home & slept)

On the new machine with a day old copy of the working /opt/zimbra
Re-configure the IP and HOSTNAME as the existing server
But do not connect to the network

Run the install again, this time without the –s
Sudo ./install.sh

Everything installs happily –
I launch FireFox and test out both the Admin interface and users interface.
Everything appears exactly as the live server at the point in time 24 hours ago.

Now all I have left to do is run a full backup on the existing server and restore it on the new server ( I hope)

I should have a cleanly installed OS and latest version of ZCS without all of the remnants of incremental upgrades and updates scattered about.

Thanks Zimbra, for a great product and to everyone in the forums for your posts. I’ve gleaned a lot from reading about everyone else’s issues.

Peace,
Dwill

[heinzg]

Interesting post Dwill!

I would have done only one thing differently the rsync from old to new host I would have done live i.e Old server still running hot sync...
Once all is across the net then another hot sync, then stop zimbra on the old server and then a last cold sync. After that old and new server /opt/zimbra dirs should be in sync, and now run the zimbra installer to upgrade the new server install.

But I like your approach!
heinzg

[dwill]

Agreed, the next rsync should be much faster copying only changes. I'm going to try running a backup (via admin panel) tonight and restoring it to the new machine. I don't see any reason this shouldnt work. (Someone please correct me if I'm wrong) **I'm only interested in users mail with this backup, since there are no configuration changes that need to come across with this process**

Thanks for the feedback

[heinzg]

with the last sync... is the users mail then not also on the new box?

heinzg

This must be a NE we are talking about, or?

[dwill]

Yes, er - sort of. I wasn't real clear in part of the explanation above -
When I made a local copy of /opt/zimbra on the old server, it was so i could resume the mail services, Then use the copy to rsync to the new machine -

That being completed now and having verified that all settings and passwords were replicated during the second install on the new box, all i now need to do is bring the actual mail items up to date. i'm thinking
zmcontrol stop on the old box
run a full backup
copy to new box & restore
bring the new box online and smile