D

Database Manager

Software component in the Cluster Service that manages the cluster database.

Dependency

Relationship between two resources that makes it necessary for them to run in the same group and dictates the order in which they are taken offline and brought back online. For example, an application resource is dependent upon the disk resources that contain its data.

Disk mirroring

Fault tolerant technique that writes data simultaneously to two disks using the same disk controller. The disks operate in tandem, constantly storing and updating the same files. Mirroring alone does not ensure data protection. If both disks fail at the same time, you will still lose data.

Disk striping

Spreading data over multiple disk drives. Data is interleaved by bytes or sectors/blocks across the drives.

Domain Name System (DNS)

Service that maps friendly names to IP addresses. DNS is used on the Internet for resolving names to Internet addresses.