With iSCSI's meteoritic rise in popularity, this question is becoming more and more common. Besides its cost being lower overall than most Fibre Channel solutions, iSCSI is also much less complex than Fibre Channel, mostly due to the fact that iSCSI is based on common Ethernet. That said, because iSCSI is currently limited to gigabit Ethernet speeds, from a performance perspective, it can't always handle the most demanding tasks that are often thrown at Fibre Channel-based storage. For small- and medium-sized organizations, though, this may not be a concern since iSCSI that uses good hardware is often very fast and more than able to handle a significant load.
In March of 2005, the college at which I am the IT Director made the switch to Exchange and, at the same time, installed an EqualLogic PS200E iSCSI array. In fact, Exchange was the first application to be run from the array. Since then, we have had no problems running Exchange from the array, which offers a variety of data backup solutions, including snapshots and replication.
Our PS200E now supports Exchange, two critical administrative SQL Server databases, dozens of file shares holding tens of thousands of files, complete virtual machines, and more. With the exception of one communication hiccup that was not caused by the array, my organization has had no growing pains with regard to iSCSI.
In speaking with a consultant at a company that provides Exchange maintenance and recovery tools, he said about the EqualLogic PS200E that "they tried intentionally to throw so much data at the array that the array and Exchange would eventually give up. It never happened." While EqualLogic is just one vendor in the iSCSI market, this statement, and the experience of many others running Exchange on iSCSISANs, bodes well for this relatively low-cost storage medium. I use EqualLogic as my example due to my familiarity and good experience with the hardware.
The answer to the question posed in this tip's title: Yes.