One of the common disk configurations I've seen for E2K7 was one RAID 1 array for the OS, another array (RAID 1, RAID 5 or possibly 10) for the database and RAID 1 for the logs. In some cases, you might take this further with a separate array for each database. With E2K10, IOPS performance was increased by up to 70% and you now could consider having the database and logs on the same array. But what about a small organization with, for example, less than 50 mailboxes and low use at that? No projected growth for the future - number of employees and mailboxes should remain constant. If you had a very tight budget, could you get away with this? I suppose it depends a lot on the disks: with 15000 RPM SAS, or SSD, almost certainly. Please mark as helpful if you find my contribution useful or as an answer if it does answer your question. That will encourage me - and others - to take time out to help you.

You probably can, and surprisingly in your case it probably doesn't matter what the disks are. You are welcome to struggle through the Mailbox Role Calculator, downloadable from Microsoft. However, understand that if you only have one database copy, which would be the case with a single server, you have a single point of failure and potential data loss. That is, if you lose the drive, you potentially lose both the databases and the transaction logs. If they are on separate drives and you take regular backups, a loss of either one probably means you can recover nearly all if not all of the data up to the point of failure.Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."

Hello Agree with Ed if you have Seperate partitions for OS, Application ,Logs, Database its very easy to manage. If you have 5 drives You can use 2 disk for Raid 1 Mirroring OS ,APP Use rest of them Raid 5 for Logs, DB Thanks Mouzzam Hussain Visit to my Blog mouzzamh.wordpress.com

You probably can, and surprisingly in your case it probably doesn't matter what the disks are. You are welcome to struggle through the Mailbox Role Calculator, downloadable from Microsoft. However, understand that if you only have one database copy, which would be the case with a single server, you have a single point of failure and potential data loss. That is, if you lose the drive, you potentially lose both the databases and the transaction logs. If they are on separate drives and you take regular backups, a loss of either one probably means you can recover nearly all if not all of the data up to the point of failure.Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."

I meant to ask if you could have the OS, database and logs on the same volume. Re-reading my first post, I see that that's not clear so I want to clarify. Otherwise, yes, I realize the risk. Personally, I would not put everything on the same drive. But someone else with no (or little) money had asked me the question and I'm trying to help them out. They also have few users (but want onsite versus something like Office 365 in the Cloud - their choice I suppose). Wouldn't Exchange function like that in a Small Business Server implementation? Everything on one drive (or preferably one RAID array)?Please mark as helpful if you find my contribution useful or as an answer if it does answer your question. That will encourage me - and others - to take time out to help you.

I answered that question!Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."

Thanks Ed. In my first post I wrote: --- With E2K10, IOPS performance was increased by up to 70% and you now could consider having the database and logs on the same array. But what about a small organization with, for example, less than 50 mailboxes and low use at that? --- I did not add OS to "database and logs" so I was not sure that was entirely clear (that I was talking about all three elements).Please mark as helpful if you find my contribution useful or as an answer if it does answer your question. That will encourage me - and others - to take time out to help you.

The I/O demands on the OS volume is usually small compared to databases and logs.Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."

The I/O demands on the OS volume is usually small compared to databases and logs. Ed Crowley MVP "There are seldom good technological solutions to behavioral problems." Quick follow up question: Since the above quote is the case, what would be a better scenario if you HAD to do one: RAID1: OS RAID10: DB and Logs RAID1: Logs RAID10: OS and DB Thanks.