This has been advertised a lot recently but thought it was worth a quick post.
The calculator is available here: http://blogs.technet.com/dpm/archive/2007/10/31/data-protection-manager-2007-storage-calculator.aspx and is based on the Exchange 2007 Mailbox Storage Requirements Calculator.
**Just a quick note to those who are attempting to get a quick understanding of the number of DPM servers that are going to be needed. The calculator uses a combination of the following to determine required server numbers:
- No. of Exchange Servers
- No. of Storage Groups per Exchange Server
- Total DPM storage required per Exchange Server
- Max no. of Storage Groups per DPM Server
- Maximum Storage Capacity for a DPM Server
The last two bits of information used here are based on 'theoretical' maximums. In other words the product has only been fully tested to these limits. I believe the product will scale well beyond these limits and therefore less DPM Servers may be required. Of course I am not advocating ignoring these limits - I am just saying that if the scalability of DPM is something you think is going to be a problem for your deployment then I would recommend considering pushing these limits. This will be relevant for only a small proportion of enterprise customers and should only be considered where thorough, appropriate testing can be achieved before deployment.
Anyway it's a great piece of work and the calculator makes design a lot easier.