1 vs 2 Servers for 75+ Mailbox deployment?

[jsmith]

I have read the system requirements, etc. but all is a little too general for me when we're talking about varying ranges of mailboxes. I am hoping for some 'real world' or 'test' experience for what works best!

We're looking at possibly deploying Zimbra Pro NE with 2 domains, Mobile support, and currently ~ 60 mailboxes total with up to 100 this year.

We would probably working with 1 or 2 Dell PE 2900 III's with dual quad-core Intel Xeon 5410 2.33GHz processors, 4GB Ram, 4 500GB SATA HDD in a RAID 10 (1TB) running Ubuntu 6.06.01 LTS 64-bit. Average mailbox would be 1-2 GB. Migrating from Outlook 2003/2007 PST's.

Would the above be sufficient hardware?
What are the (dis?)advantages to having a multi-server (2) setup versus a single server?
What about single server and cold standby server? (Supported under NE?)
Any other recommendations/suggestions while we consider this?

Thank you to everyone in this community. You are all very knowledgeable. I have followed the forums for ~ 6months and have learned a great deal about what to expect from reading lots of posts, without having run the software at all!

-Jake

[mmorse]

I'll let other's debate merits of HA vs multi-server setups/experiences
Just wanted to point one thing out before I forget, noticed you said "Ubuntu 6.0.6.01 LTS 64-bit". If you're doing NE until Bug 16666 - 64-bit Ubuntu build is done, you really should run one of the supported platforms listed here: Zimbra Product Portal - Release 5.0

[jsmith]

On that note - it'll have to be Ubuntu 6.06.01 LTS 32-bit
Regardless of HA, Multi-server, or Single-server; the hardware would be sufficient?

[jsmith]

So how long after a bug is 'Resolved' till its officially supported?
Bug 16666 - 64-bit Ubuntu build is now resolved so does that mean its officially supported now? or next release?

Guess part of that was answered by the time I posted this

[mmorse]

When we release a binary

[jsmith]

Thanks

[davidfsmith]

we run 3 domains, 500 users on a Dual Xeon with 12Gb of RAM and 1Tb RAID 10, copes fine most of the time (had an issue recently that support sorted) the biggest issue was migrating the 600Gb of user data, and then the first day as everyone's mail client grabbed their emails....