Re: Large Zimbra deployments on VM

["Daniel A. Ramaley" <daniel.ramaley@drake.edu>]

We have about 12,000 accounts running on a mixed virtual/physical 
environment. Our 2 LDAP servers run on XenServer VMs. The 2 MTAs are on 
physical boxes now, but will be migrated soon (waiting for a RAM upgrade 
to the Xen cluster). Our 2 mailbox servers are a different story. We'd 
like to virtualize those, but will probably leave them as physical boxes 
for awhile simply because they require a lot more CPU & RAM than the 
LDAPs or MTAs.

The hardware we were previously using for the LDAPs was higher capacity 
than what they really needed (8 CPU cores, 8 GB RAM). In the virtual 
environment we provisioned considerably less (2 CPUs, 2 GB RAM) and they 
are doing just fine. I'll be able to recover some resources when 
migrating the MTAs as well.

We managed to do the switch to virtual LDAPs with little downtime simply 
by provisioning 2 new VMs, adding them to the Zimbra cluster as LDAP 
replicas, promoting one of the new replicas to master, and shutting down 
the old hardware. We expect minimal downtime when virtualizing the MTAs. 
If we decide to virtualize the mailboxes, we'll again have minimal 
downtime by provisioning new VMs and then migrating accounts to them.

In short, make sure your virtual environment has the capacity, and 
ideally is using a high-speed SAN for storage, and you should be good.

On 2010-02-17 at 18:35:42, you wrote:
>We are currently running ZCS 5.0.19 NE on Red Hat 5 on hardware.  Our
> current servers are coming up on the end of their service contracts
> later in the year and our Central Server group is encouraging us to
> consider going to a VM setup instead.  We are currently on the path
> to upgrade to 6.0.5 by summer, so that is where we would be when we
> would switch to VM if we decide to go that way.  I have read several
> forum posts about VM setups working pretty well with ZCS, but I
> haven't seen anyone with more than around 1000 users talk about using
> VM.  We have VMWare here on campus, so that would be our VM
> environment.  We have around 30,000 accounts (around 22,000 student
> accounts, many of which are lightly or not used).
>
>Are any of you running a large Production system in a VM environment? 
> Any suggestions on questions to ask our Central Server guys about our
> current VM environment to determine if it can support our ZCS setup?
>
>Thanks,
>
>Tim Ross
>Application Administrator
>Collaboration Support Group
>

-- 
Daniel A. Ramaley
Network Engineer 2

Dial Center 118, Drake University
2407 Carpenter Ave / Des Moines IA 50311 USA
Tel: +1 515 271-4540
Fax: +1 515 271-1938
E-mail: daniel.ramaley@drake.edu