Two zimbra server syncing with each other.

[aldennis]

Hi,

Were running ZCS 6.04 Open source for two years now on Ubuntu 8.04 guest in Win2k3 host (both 32bit). Its a single server install.

Our zimbra server uses a public IP and is also the single mx in our domain. I would like to setup two mx for failover in case one of the two ISP's were using suddenly cuts-off or a server fails.

I would like the two zcs server to have the same message content. That is either one of them is updating one another with the latest email received/delivered.

Is it possible? How can I do this? I'm not good at scripts but I can follow directions.

Thanks

[iway]

See: Bug 11423 – disaster recovery through server to server sync (beta)

[aldennis]

Reading from the comments, this has been going since Franklin. We started using ZCS during 5.0 up to 6.04 at the present.

Were just too hasty to drop Domino for Zimbra two years ago due to flooding spam and drastic cost cuting. Geez, maybe we should consider going back to domino next year if this does not come up in Zimbra 7.

DRBD+Heartbeat and two zimbra server...hmm..must give it a shot.

Thanks for the info.

[ewilen]

If network latency/bandwidth between the two servers aren't issues, then I agree DRBD is probably the best way to get real-time syncing. But an alternative might be imapsync--for email, at least. Here are a couple related links; you might find more if you search the forums:

Synchronising to a Remote Backup Machine
Scripts to sync to a remote Zimbra backup machine - Zimbra :: Wiki

[aldennis]

Thanks for all the info.

Our zimbra users are increasing from 50 to 90+. I think its time have a working standby server.

[aldennis]

After reading the topic you refer to me, I 've got the following questions:

1. Can I install imapsync on a different box and use it to sync two zimbra servers?

2. If zimbra1 fails and I've put zimbra2 online does it sync back to zimbra1 if zimbra1 becomes online (deleting new messages and copying exactly what zimbra1 contains) or zimbra2 will update messages in zimbra1? or it would not sync at all?

[ewilen]

Sorry, I don't know the answers to either of those questions. I think you can install/run imapsync anywhere. As for your second question I'd assume it depends on the script you wrap around imapsync.

There are a number of threads discussing various approaches to backup and DR for both FOSS and NE. Before zeroing in any one I'd consider bandwidth & latency between the primary and backup, how up to date the backup must be, whether you're willing to stop zimbra periodically, whether you're willing to invest time or money in storage layer snapshot technology, or in VM replication, etc.

I don't personally use imapsync--I need to protect calendar data as well as mail. DRBD is attractive but I'm not sure our WAN link between servers is sufficient. Therefore while I wait for Zimbra to develop a native replication feature, since I have NE, I rely on periodically rsyncing the NE backups along with redologs.

[aldennis]

Ok, I'm not implementing this yet until I have answers to my questions.

Anyway I'm considering cold backup doing it with rsync scheduled via crontab. I'm not doing it over WAN since my backup server is inside the same network.

Also I'm putting up a Zimbra Desktop server where all accounts are in there for up to the minute retrieval of email. (In case I switch on to backup when my primary fails.)

As for remote backup/sync of zimbra server, I'd rather wait for that feature in Helix.

I just want to have a backup fail over even there a few hours downtime involve. Not necessarily HA but something I could switch on in case my primary server fails.

[ewilen]

For rsync with FOSS you'll have to stop Zimbra services. Read this thread for tips on minimizing downtime: Zimbra OSE backup without stopping the services

But I would also search on DRBD because there have been some threads on that which make it seem very good for your purpose. These are the chief ones:

[SOLVED] Zimbra on DRBD
How to: cold standby server (no cluster) (read down a bit, the opening post is about NE cold standby using rsyncing of the NE backup data)

[aldennis]

Ok this is truly usefull. I'm still new to Linux though, its only 2 days ago that I've learned how to use crontab and is now trying out ssh with rsync.

I'm gonna try this one step at the time. I'll start with the less complicated stopping services then doing rsync then moving with lvm (I still going to do a research on this). I have a whooping 90GB Zimbra server and copying it takes 2+ hours on gigabit network. Though downtime is not an issue for most of our users but I like the idea of less than 3 mins. downtime with lvm mirroring.

Goodthing theres GUI frontend in Ubuntu for rsync and crontab.

Thanks for the help.