Raid for Exchange 2007 and Hardware selection

[geekinput]

Hi,

I would like to start by making clear that I am not an Exchange guru. I work
for a small but very busy company as one of the System Admins. I need some
input on possible storage designs and hardware selection for Exchange 2007
migration. I am in the process of getting quotes from our server vendor and
want to make sure I order the right stuff.

We are not into spending 20K on a server, but if we need to spend 12-15K to
get the best performance, we'll be able to justify the amount.

We currently have about 50 employees and 120 mailboxes. Our average
sent/received is 30/120. We currently have a quota of 3GB per mailbox and
some member of management have 6GB. The average message size is 200KB but it
can go up to 50MB or even more some times.

We are not planning on having an edge server or using the UM role, so the CAS,
HUB and Mailbox roles are going to reside on the same box.

I have a few questions about the partition design and array sets:

I know is recommended to have the exchange logs, system partition and
databases on their own separate disks.

Is a design like this a good design or can it be improved?

1 Raid 1 set for OS (2 x 146GB)
1 Raid 10 set for Logs ( 4 x 146)
1 Raid 10 set for DBs (6 x 146)

I am planning, and I am opened to other ideas, to create 2 storage groups and
put a database on each SG that way I can place 60 users on one DB and 60 user
on another DB.

Should I create two LUNs on the DB Raid 10 disk set, one for each SG?

The same question applies to the Logs. Should I create a LUN for each db
logs?

or

Should I create 4 disk sets and isolate the DBs and Logs for each SG.

What about the TEMP folder? Should I create a LUN for it?

Also, am I going to need multiple Raid controller to be able to create
multiple types of array sets?
Ex. Raid 1, 10, etc. on the same server.

Currently I'm looking at a Dell PowerEdge T710 with this specs as an option
and would like to know your opinion about it.

-2 Intel® Xeon® E5630 2.53Ghz, 12M Cache,Turbo, HT, 1066MHz Max Mem (Quad
core)
-16GB of memory
-the chassis can hold up to 16 HDs.
-If I need to go with 16 146GB 15K RPM Serial-Attach SCSI 6Gbps 2.5in my
quote still under 14K which is OK if I have to.

Your help will be really appreciated.

J.D.

 

[ShackDaddy]

Devil's advocate here. I would cut your TLog RAID down to a RAID1 and not RAID10, and I would use the extra two drives and add them to your database array.

Also (and alternately), you could probably save a LOT of money by buying quality SATA drives and using fewer of them. Your database array is a bit overkill for your organization size, except that you have chosen small SCSI drives, so you have to have more of them. Even a 4-disk RAID 10 with good 1TB SATA drives would be way better, since you could then have plenty of room for recovery operations.

Exchange 2007 has really optimized disk IO quite a bit, so it's not nearly as critical to separate out every component as it was with earlier versions of Exchange. And in your smallish environment, there's real danger of overspending if you spec your server like an Exchange 2003 server supporting 1200 mailboxes, which it currently looks like (except for the total storage amount).

If you aren't going to use SATA, at least bring your log partition down to just RAID1 for the savings, and then decide whether you want to expand the size of your DB array.

One of my clients with 310 mailboxes totaling more than 400gb in size mainly wishes one thing: that he'd allocated more disk space when he first spec'd the server. You want to have plenty of free space so that you can restore copies of your databases to the same volume. I see no potential on your server for processing or memory bottlenecks, but the size of your database array can't be skimped on.

Dave Shackelford MVP
ThirdTier.net
TrainSignal.com

 

[geekinput]

Hi ShackDaddy,

Thanks for your comments.

You are right about the Tlog partition size. I will go with Raid 1 instead. As far as the drives, we will go with SCSI drives and will increase the amount of storage.

Let me ask you, do you think that having so many cores (8) and so much memory could cause a bottleneck?

The reason I'm asking is because the difference between 8, 12 or 16 GB of memory is just a few hundred dollars and if it's not going to cause any problem, I rather be prepare to scale up if I need to.

As far as the CPUs, it is cheaper to go with two Intel® Xeon® E5630 2.53Ghz (4) cores each than one Intel® Xeon® X5680, 3.33Ghz (6) cores.

Based on the chassis/mother board configuration, Dell does not give me the option to use dual cores, at least not from the website.

 

[ShackDaddy]

Having cores and memory won't cause a bottleneck. If you wanted to you could start with a single quad-core and add another if you seem to need it. It would be great to start with 16gb of memory, since it's primarily memory that allows the reduced disk IO.

Dave Shackelford MVP
ThirdTier.net
TrainSignal.com

 

[geekinput]

A few questions:

How many DBs would you set up for 120 mailboxes with 3GB quotas?

Where would you place the TEMP folder and the MTA Queues?

With the following configurations, how many LUNs would you set up? which one would you go with?

1 Raid 1 set for OS (2 x 146GB)
1 Raid 1 set for Logs (2 x 146GB)
1 Raid 10 set for DBs (10x 146GB)

or

1 Raid 1 set for OS (2 x 146GB)
1 Raid 1 set for Logs (2 x 146GB)
1 Raid 5 set for DBs (8 x 146GB)

 

[ShackDaddy]

For your size environment, I would try and keep the databases under 70gb, so if you are just setting things up, you might split your mailboxes into four different databases, each in its own storage group. Most of the users won't be using their 3gb capacity, so I'm guessing that it will be quite a while before you are even storing 200gb in mailbox data.

Keep Temp and MTA on the OS drive, since it will have plenty of space.

If it were me, I think I'd go for the second option because it gives you more storage space. I would expect performance to be fine under the sort of load you are talking about. If the server was going to be more stressed on the IO level, I'd opt for the first option.

Dave Shackelford MVP
ThirdTier.net
TrainSignal.com