Continuous Cluster Replication and Direct Attached Storage: High Availability Without Breaking the Bank
When Exchange Server 4.0 was introduced, internal drives (or, for the well-funded, direct attached storage) were widely used. When the author first started working with Exchange in the mid-1990s, many of the organization's Exchange Servers used 2GB internal drives; these servers provided file and print services, and also ran SMS. For a few of the more robust servers, they had two 2GB drives, and the database resided on one drive, the log files on the other. None of the servers used RAID drive sets, and clustering was a much-discussed dream. When clustering was eventually introduced for Exchange, it included shared storage for the mailbox databases and only protected Exchange Server from a small subset of issues, such as blue screens.