[SOLVED] Moving from RHEL4 to CentOS5... is it possible?

[underdog]

hi there,
i've been looking through the wiki and putting in as many search terms in the forum as i could to find an answer but i found nothing definitive.

The scenario is:
i have a managed server running RHEL4 with

Release 5.0.1_GA_1902.RHEL4_20080109193657 RHEL4 FOSS edition

and i have a new, internal Centos5 server running:

Release 5.0.9_GA_2533.RHEL5_20080815132719 CentOS5 FOSS edition

What i want to do is kill of the RHEL4 edition and move all mailboxes etc to the new Centos5 internal server.
i read here:
Moving ZCS to Another Server » Zimbra :: Blog

which at the top mentions the caveat that states that i need the same version of zimbra on both servers, this is fine, i can update the ol server and test it before migration but does it matter that one server is running RHEL4 and the other is running Centos5?

This would be a mjor spanner in the works........
anyone feel like enlightening me as to what i can do to move from an old server to a new one?
seems like it would be a pretty common problem a lot of people would have encountered at some point?

Thanks for any help you can offer.

[cedbobking]

We're in the process of doing roughly what you describe right now. Our original Zimbra server was spare hardware on which we installed 32-bit RHEL 4, ZCS 4.2 Network Edition and started with a trial license. We were trying it out and decided to go live as soon a we started working with it. The system is now running out of disk space. I have recently built a new server with 64-bit CentOS 5.2 and ZCS 5.0.9 Network Edition.

Just yesterday, I performed a trial migration and it seemed to work great. My first step was to upgrade the production RHEL4 box to 5.0.9. Then I performed a backup to a USB drive using zmbackup. Then I simply restored to the new CentOS 5.2 server using zmrestore. Everything seemed to transfer just fine. Sometime this week I will probably do the backup/restore process one more time and commit to the new server immediately afterward.

I don't know how FOSS edition backs up, but I suspect that if the backup will restore lost users and data to your production server, it should work for a migration.

I believe that there isn't much definitive out there because so much can go wrong. If you have a test box, you can always try out different scenarios with impunity. When you find one that works, update the wiki articles.

[underdog]

OK,
So this IS possible, however not without some difficulties. I've managed to install accross servers now however my new server has decided not to send and recieve anymore, it just keps thiings in the queue. However i have a feeling this is something more to do with my system at large rather than zimbra itself.
I can now run zimbra and everything functions normally, mailboxes in, calanders in etc however i just cant send or receive (it does actually send but it doesnt arrive at the destination and just gets put in the deffered queue)
RHEL4 -> CentOS 5

[cedbobking]

Glad to hear that you were able to move the mail/calendar/etc. from RHEL4 to CentOS 5.

Not being able to send email might be a networking, firewall or name resolution issue in CentOS. Do /etc/hosts /etc/sysconfig/network /etc/sysconfig/networking-scripts/ifcfg-eth0 /etc/resolv.conf /etc/sysconfig and /etc/sysconfig/iptables all look good to you?

Maybe you're not allowing incoming SMTP servers in the Zimbra configuration. (I think it's a good idea to have localhost and your local ip in that list at the very least.) These are the networks/hosts from which I allow SMTP traffic. (There's a place for this in the Zimbra Administration pages also if you like to click before you type.)

From my live production server...

[zimbra@mail ~]$ zmprov gas -v | grep MtaMyNetworks
zimbraMtaMyNetworks: 127.0.0.0/8 a.b.c.d/32 e.f.g.h/20 i.j.k.l/32
[zimbra@mail ~]$

* IPs hidden to protect the innocent
* a.b.c.d/32 is the IP of my Zimbra server
* e.f.g.h/20 is inbound mail from Postini
* i.j.k.l/32 is another host from which I allow mail

Can you send email to yourself via the web interface from the localhost? Others in your domain? Other domains you might host on your Zimbra server? The outside world, like a yahoo.com account?

Can you go to a system outside your firewall and telnet yourdomain.tld 25 or telnet yourdomain.tld smtp? (You might have to dig -t mx domain.tld and use a specific IP address) Try sending yourself a simple email using Simple Mail Transfer Protocol - Wikipedia, the free encyclopedia

You might be want to try this from your Zimbra host to another working server where you know an administrator. It would tell you if you can send email. Please clear it with them first. I can telnet myisp.com smtp just fine from my Zimbra server and send a simple message.

If you have some more precise information about the SMTP traffic, perhaps someone could provide some specific suggestions.

Good luck.

[underdog]

OH MY GOD!
Don't take this the wrong way but..
I love you to the very extents of which a man should ever love another man!

I've been awake for 48hours trying to figure out what wrong going over dns settings, my wan devices, iptables, wiki's, bind manual the lot and i completely over looked the zimbraMtaMyNetworks thing staring me in the face.....

I had my old ip in the center.... all i needed to do was

zmprov modifyServer mailserver.myservername.com zimbraMtaMyNetworks '127.0.0.0/8 192.168.80.0/24 [public ip here]/32'

Ahhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh