Design Help and Questions...

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

S Reichard - 21 Jul 2006 20:09 GMT

I have several options...

I am consulting for a school that has about 5500 users. About 4500 are
students and the rest are faculty. They had purchased a server with dual 3.6
ghz processors, 3 x 36 GB drives configured as RAID5, 8GB of memory, and is
tied to an EMC SAN with 1TB (10 X 146GB) of space. I know Exchange wastes
memory higher than 4GB and that it is not recommended to put Exchange on
server with the PAE extension in the boot.ini. They also have one more
server that is suppose to be the front end. With this said what do you think
the best design? How well does Exchange work in a Virtual Server
Environment? Here is what I was thinking...

Configure a front end server with dual nics and configure network load
balancing. Place this server in a DMZ and all of the students will use this
to access their email. On the backend, load virtual server on the Dell
server with two nics and configure two LUNS on the SAN for two virtual
backend servers. One LUN will be about 400 GB for the staff and will hold
the VHD for the first backend server in the topology and the other LUN will
be 600GB for the students and will hold the VHD for the other backend server.
Each virtual server will have a dedicate nic. All staff will use Outlook to
connect to the servers and each server will be allocated 3GB of memory. Is
this a good scenario? Virtual Server will be R2 along with all Windows 2003
R2 Enterprise Edition. Exchange 2003 Enterprise Edition on each server as
well.

Basically I am trying to work with what I was given and make something
robust and utilize all of the hardware along with creating an easy failover
plan if the dell server crashes. I also wanted to separate the processing
between the faculty and staff...

Let me know what you think!

Steve

Reply to this Message

Al Mulnick - 21 Jul 2006 23:46 GMT

A couple of thoughts jumpt out:

1) " I know Exchange wastes memory higher than 4GB and that it is not
recommended to put Exchange on server with the PAE extension in the
boot.ini." That's changed. See here:
http://msexchangeteam.com/archive/2005/07/05/407330.aspx

2) Unfortunately, Exchange is a highly volatile disk-dependent application.
What I mean by that is that you can't accurately predict the disk usage for
a given moment and Exchange is highly dependent on disk IOPS for
performance. Virtual server is not recommended for Exchange primarily
because it cannot handle the high-load for disk IOPS. It has a built in
bottleneck due to it's nature. Will it run there? Sure. Is it a good idea?
No.

3) putting a FE server in a DMZ? You may want to reconsider that in favor
of putting ISA in the DMZ only.

With what you have to work with, disk is likely going to be a bottleneck at
some point in the future (after you deploy) anyway. Take what I'm telling
you with a grain of salt and verify the information. Also verify the
support policy with regards to Exchange on a virtual server; you don't want
your client to be pushed down the creek without locomotion apparatus, right?

>I have several options...
>
[quoted text clipped - 39 lines]
>
> Steve

Reply to this Message

S Reichard - 24 Jul 2006 16:59 GMT

So with Windows SP1 they support PAE now. OK...

I have run Exchange in a virtual environment before with no issues. Major
differences between previous configuration and this one. Here I have more
users and a SAN environment. I was figuring on configuring three luns. one
for one vhd, another for the second vhd and then the third for the logs.
Each virtual machine would have 3 gb of memory and two disks. one for the
dbs and one for the logs. below is the microsoft support article for
exchange in a virtual environment.

http://support.microsoft.com/?id=320220

http://www.microsoft.com/technet/prodtechnol/virtualserver/2005/proddocs/default
.mspx?mfr=true

Everything I read mentions that if it is setup properly, then it could run
very well.

Thoughts?

Steve

> A couple of thoughts jumpt out:
>
[quoted text clipped - 64 lines]
> >
> > Steve

Reply to this Message

Al Mulnick - 26 Jul 2006 00:40 GMT

I've seen those. I agree it could, but only up to the point that the
Virtual Server can handle the IOPS. There is going to be a limit on the IOPS
that is below that of a physical. Kind of like with clusters. Also, I read
those articles as being something they put out so they would not look like
they didn't support their rivals and their own virtual server team. I don't
see that as something being done because the Exchange team thought it was a
good idea and should be supported that way. The difference is that there
could be somebody out there that says, "I told you so" if things go bad.

There is an inherent cost with the virtuals of the guest OS and software
overhead. Be cautious of that.

> So with Windows SP1 they support PAE now. OK...
>
[quoted text clipped - 102 lines]
>> >
>> > Steve

Reply to this Message