Microsoft eliminated single instance storage in Exchange Server 2010 to decrease database I/O, but the loss of SIS means data stores that were migrated from previous versions
Instead of single instance storage (SIS), Exchange Server 2010 uses database compression technology and new tools that purge mailboxes and keep database sizes down. But database size will increase for some customers, and they will need larger disks and larger backup systems.
To overcome that problem, Microsoft now approves of using less-expensive storage. For example, Microsoft condones the use of SATA drives with Exchange mailbox servers.
When I heard Microsoft was advocating the use of low-cost hardware, my initial reaction was that it was a marketing ploy. I didn't think any Exchange shop worth their salt would ever consider low-cost hardware to run Exchange 2010. However, I've seen numerous companies successfully use cheaper hardware -- particularly low-cost storage. I've even seen a couple small businesses successfully configure PCs that were equipped with SATA arrays to act as Exchange 2010 mailbox servers.
If you're running Exchange 2010 in an enterprise, I don't recommend using low-end storage for anything other than personal archive mailboxes. However, for those not in enterprise environments, low-cost hardware is a realistic option. To give you a concrete example, I decided to see what it would take to run Exchange on low-end hardware and how much money you can save by implementing low-cost storage.
Before I begin comparing server hardware, let's review Microsoft’s Exchange 2010 mailbox server recommendations. For the sake of this tip, let’s assume we need to create a mailbox server that can host 200 mailboxes and that each mailbox has a 5 GB quota. Let’s also assume that the server will only be hosting the mailbox server role. With that in mind, here are the hardware requirements:
|Component||Microsoft recommendation||Required hardware|
A minimum of two processor cores consuming no more than two sockets. Microsoft recommends a maximum of 12 cores for mailbox servers.
|4 CPU cores|
|Memory||4 GB, plus an additional 3 to 30 MB per mailbox||Roughly 10 GB of memory is required to support 200 mailboxes.|
Microsoft does not provide firm guidelines regarding storage requirements for mailbox servers. It does indicate that the Mailbox Server Role Requirements Calculator should be used.
The hardware the calculator recommends is based on mailbox usage patterns and disaster recovery requirements.
Because every organization’s mailbox usage patterns are different (resulting in differing I/O requirements), I will only look at database space requirements. I will provide hardware configurations that will result in acceptable I/O for the example server that was outlined earlier.
The server will require approximately 2.5 TB. The database should never grow beyond 1 TB (200 mailboxes with a 5 GB quota), but you need to provide enough space to accommodate a full copy of the database in case a database repair should ever be required. I will also provide an extra 20% for overhead.
|Operating system||N/A||For the purposes of this tip, I will assume that a dedicated hard drive is used for booting the operating system and for storing the page file.|
To see how low-end storage impacts costs, I priced a typical server that meets the requirements stated above. I chose a Dell PowerEdge R515 because it is designed for small- to medium-sized businesses. I based my estimate on the following specifications:
- Single AMD Opteron 4130 4 core CPU
- 16 GB of memory (4 x 4GB)
- Five 1 TB 7.2K RPM Serial Attached SCSI (SAS) drives. One drive is for the OS, the other four are configured as a RAID 5 arrays, providing 3 GB of storage.
The estimated cost of this server is $4458. This estimate only includes server hardware. It does not take software licensing costs into account.
After establishing the cost of a typical Exchange 2010 mailbox server, I reconfigured the specifications to see what the server would cost if I used five 1 TB SATA drives instead. After making the switch, the price dropped to $4058, saving me $400.
At first, a savings of $400 doesn’t sound like much. Especially when you consider that the total price of the server is going to be around $10,000 after you include the cost of software licenses. However, there are two important things to keep in mind.
Exchange 2010 mailbox servers operate as a part of a database availability group (DAG). DAGs can consist of up to 16 servers. When you multiply the $400 savings by the total number of mailbox servers you will need, the savings start to add up.
The second point is that hard drives tend to be replaced more frequently than any other server component. Even if you only save a little bit of money on each drive, consider how many times you will need to replace the drive over the server’s lifetime.
ABOUT THE AUTHOR:
Brien Posey is a seven-time Microsoft MVP with two decades of IT experience. Before becoming a freelance technical writer, Brien worked as a CIO for a national chain of hospitals and healthcare facilities. He has also served as a network administrator for some of the nation’s largest insurance companies and for the Department of Defense at Fort Knox.
This was first published in June 2011