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Best setup for RAID10 Exchange 2007 Drive Arrays

amedexitt asked
Medium Priority
Last Modified: 2010-04-27
I was having a discussion with my DBA about how we are going to split the Exchange 2007 Databases.

To give you an idea, we are going from one 500GB store (a Testament to Exchange 2003 I gotta say!)
into 4-5 Storage Groups with 4 Databases a piece in all likelyhood. There are about 300-400 user mailboxes.

We have 12 300 GB 15K SAS drives in an MSA Array.. so the RAID 10 Storage total is 1.8 Terrabytes.

We are between three configs:

A)All 12 drives into one RAID10 array, giving us 1.8TB and splitting the space into individual partitions for 2-3 databases to each partition.

B)2 6 Drive RAID10 arrays giving us 900GB each, and 2-3 databases per partition, with 3 partitions of 300GB

C) 3 4 Drive RAID 10 arrays giving us 600GB each, and 2 partitions with 2-3 databases each.

Which config would give us the best performance? We are going to have heavy stores with light ones to try and balance the load.

What is the most databases you would recommend having transaction logs on a mirror array? Would 3-4 sets of Transaction Logs be OK for each one?

In any event, it's going to be much faster than the RAID 5 everything is sharing right now.
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Expert of the Year 2007
Expert of the Year 2006
Transaction logs are grouped by storage groups.
So if you are going to split out the database in to storage groups you need to consider the transaction log location as well.

I would not be looking to partition the space at all.
How many arrays can the card cope with?

If this was me, with the full set of drives I would probably be looking to do a 2:1 split, for every two storage groups (with each group on its own array) there is a transaction log location.

Six arrays, four for storage groups, two for transaction logs.

Its only 400 users, so you would be hard pressed to really screw it up.


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The Transaction logs and the OS drive arrays  off the DL380 will be off their own array controller (P400). There are 8 total drives 72GB 15K SAS each

The Database RAID 10 is on its own high end array controller(P800) with the 12 drives available.

Is there still a 5 Database Limitation in Exchange 2007 per Storage Group, or how many databases would you recommend per SG?
Expert of the Year 2007
Expert of the Year 2006
It would have helped if you indicated that the transaction logs were already being managed. Most questions regarding storage configuration do not take in to account the the transaction logs so I have to answer with those included.

E2007 Standard edition has the same limits per sg as Exchange 2003 Enterprise edition. Enterprise Edition takes it up to 50.

What I usually do is max out each Storage Group as I go along. It depends on how you want to manage it though. There are various strategies that can be used, each have their own positives and negatives.
One thing you might want to consider is simply splitting the drives in to two sets, each with a hot spare, no partitions, a storage group on each and 4 databases per SG.

Any public folders to worry about?



Public Folders are used, but the store for Public folders is rather small, only 1GB in size.

I'm sorry I didn't explain about the arrays for OS and Transaction logs being on a different controller than the RAID10 array.

Since I've never used a RAID10 array for Exchange DBs, I'm assuming the performance is much faster than a RAID5 correct?
Expert of the Year 2007
Expert of the Year 2006
RAID 10 is the fastest type available, and I like to use it for transaction logs if possible. Haven't used it much for databases though because of the high cost of disks. Still use RAID 5 for many sites for the databases. The idea being that the transaction logs are on faster disks so they keep ahead of the database when it comes to writing.



Well the cost isn't the issue as we already have the 12 300GB drives in the office ;) Since we have the 8 drives for the main unit, minus 2 from OS, we have 6 available for Transaction Logs/etc so perhaps we will do a Raid 10 array for those 6 and give us 200GB for the Transaction Logs?
Expert of the Year 2007
Expert of the Year 2006
For T logs you don't really need to worry too much about space, because they are dynamic. I usually like to have two days of space on the T log drive so that if the backups go wrong the server continues to run correctly.



Thank you very much Sembee, I appreciate the responses.
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