Direct-attached storage

From Wikipedia, the free encyclopedia
Jump to: navigation, search

Direct-attached storage (DAS) is digital storage directly attached to the computer accessing it, as opposed to storage accessed over a computer network. Examples of DAS include hard drives, optical disc drives, and storage on external drives. The name "DAS" is a retronym to contrast with storage area network (SAN) and network-attached storage (NAS).



The main protocols used for DAS connections are ATA, SATA, eSATA,[1] SCSI, SAS, USB, USB 3.0, IEEE 1394 and Fibre Channel.

Storage features common to SAN, DAS and NAS[edit]


Advantages and disadvantages[edit]

The key difference between DAS and NAS (network-attached storage) is that DAS storage is only directly accessible from the host to which the DAS is attached. A DAS does not incorporate any network hardware and related operating environment to provide a facility to share storage resources independently. The storage presented by a DAS to a connected host can of course be shared by that host. A SAN (storage area network) has more in common with a DAS than a NAS with the key difference being that DAS is a 1:1 relationship between storage and host whereas SAN is many to many.

See also[edit]


Englander, I. (2014). The architecture of computer hardware, systems software, & networking: An information technology approach (5th ed.). Retrieved from https://online.vitalsource. com/#/books/9781118803127