To increase system availability and help protect against data loss, the Internet Platform and Operations group used hardware RAID with the hardware controllers. The drive performance, type of server, and the data type to protect against were considerations in determining the level of hardware RAID protection needed. For example, RAID 1 provides adequate protection for Web Servers but RAID 1+0 is more suited for database storage requiring high performance and fault tolerance.

The following table lists the hard disk capacity and RAID type used by different servers in this configuration.

Table 2 – Server farm hard disks

*For details about the drives in the SAN, see the "SAN Configuration" section later in this paper.

Information about the different types of RAID types is widely available from resources such as Planning the Layout and RAID Level of Volumes in the Microsoft Windows Server 2003 Deployment Kit on Microsoft TechNet.