I am planning to deploy two Exchange 2013 servers, probably on Server 2008 R2 Enterprise, but possibly on Server 212 Standard. The two servers will have identical drive configurations. To achieve high availability, the servers will make up one DAG.
The environment includes about 30 light mail users, 30 medium users, and 30 heavy users.
I was thinking of having the OS and Exchange on a RAID 1 array of 2 x 300 SAS drives. I was also planning on creating two RAID 1+0 arrays. Each of these arrays would probably consist of 4 x 450 GB SAS drives. All of the arrays would be managed by one controller.
For data protection reasons, the database files could be on one array, while the transaction logs are on the other. I'm concerned that this could hinder performance because a relatively large amount of write operations would be concentrated on the log array. Since the logs involve more write operations than do the databases, would the servers perform better if each of these 1+0 arrays housed both some databases and some logs, thereby splitting the write operations between the two arrays?
Although it is very informative, the following article does not address this in a definitive manner.
http://technet.microsoft.com/en-us/library/ee832792%28v=exchg.150%29.aspx