Direct Attached Storage
Direct Attached Storage is a dedicated storage device which is directly connected to a server. The term Direct Attached Storage is often abbreviated to DAS. Derived from the original meaning, the term sometimes refers to a conventional server-centric storage system in which DAS devices are mainly connected; this definition is used in the context of explaining and comparing storage network architectures.
A typical DAS device is a SCSI storage device such as an internal disk drive, a disk array or a tape library that is connected only to a single server by a SCSI bus cable. Such a DAS device is accessed only by the server to which the device is directly connected. SCSI storage devices sometimes have two or more SCSI interfaces which can connect to different servers. But such a storage device is also considered a DAS device rather than a SAN device, because only one server can actually access the storage device and the other servers are merely prepared...