Capacity Planning – Yes Transaction Log Space is Critical to Keeping your Databases Healthy and Mounted

@Brian - Your comments bring up a good point.  So first off, our guidance is is to design your Exchange deployment for the end state; in other words where you expect to be at the end of the hardware lifecycle. Now many times that may not be realistic as organizations change and can grow in size.  It's important to understand that with any IT solution, you have to do proper baselining and trending analysis to determine how the message profile evolves and adjust the design as appropriate.  This means that if you onboard a signficant number of users or the message profile significantly increases such that it can impact the capacity planning originally performed, then you need to re-architect the solution and make adjustments where necessary (e.g., add more disks and more databases, reducing the footprint per database).

Ross