A typical DAS system is made of a data storage device (for example enclosures holding a number of hard disk drives) connected directly to a computer through a host bus adapter (HBA). Between those two points there is no network device (like hub, switch, or router), and this is the main characteristic of DAS.
Most functions found in modern storage do not depend on whether the storage is attached directly to servers (DAS), or via a network (SAN and NAS). In enterprise environments, direct-attached storage systems can utilize storage devices that have higher endurance in terms of data workload capability, along with scalability in the amount of capacity that storage arrays can achieve compared to consumer-grade NAS and other storage devices.[2]
Advantages and disadvantagesedit
The key difference between DAS and NAS is that DAS storage does not incorporate any network hardware and related operating environment to provide a facility to share storage resources independently of the host so is only available via the host to which the DAS is attached.
DAS is typically considered much faster than NAS due to lower latency in the type of host connection although contemporary network and direct connection throughput typically exceeds the raw read/write performance of the storage units themselves.
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 alsoedit
Secondary storage device versus tertiary storage device or nearline storage — storage that remains attached versus storage that is attached or detached as needed
direct, attached, storage, this, article, needs, additional, citations, verification, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sources, news, newspapers, books, scholar, jstor, . This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Direct attached storage news newspapers books scholar JSTOR July 2011 Learn how and when to remove this message Direct attached storage DAS is digital storage directly attached to the computer accessing it as opposed to storage accessed over a computer network i e network attached storage DAS consists of one or more storage units such as hard drives solid state drives optical disc drives within an external enclosure The term DAS is a retronym to contrast with storage area network SAN and network attached storage NAS Typical DAS featuring USB and legacy Firewire connectors Typical NAS using ethernet for main connectivity Contents 1 Features 2 Storage features of SAN DAS and NAS 3 Advantages and disadvantages 4 See also 5 ReferencesFeatures editA typical DAS system is made of a data storage device for example enclosures holding a number of hard disk drives connected directly to a computer through a host bus adapter HBA Between those two points there is no network device like hub switch or router and this is the main characteristic of DAS The main protocols used for DAS connections are Parallel ATA SATA eSATA 1 NVMe Parallel SCSI SAS USB and IEEE 1394 Storage features of SAN DAS and NAS editMost functions found in modern storage do not depend on whether the storage is attached directly to servers DAS or via a network SAN and NAS In enterprise environments direct attached storage systems can utilize storage devices that have higher endurance in terms of data workload capability along with scalability in the amount of capacity that storage arrays can achieve compared to consumer grade NAS and other storage devices 2 Advantages and disadvantages editThe key difference between DAS and NAS is that DAS storage does not incorporate any network hardware and related operating environment to provide a facility to share storage resources independently of the host so is only available via the host to which the DAS is attached DAS is typically considered much faster than NAS due to lower latency in the type of host connection although contemporary network and direct connection throughput typically exceeds the raw read write performance of the storage units themselves 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 editSecondary storage device versus tertiary storage device or nearline storage storage that remains attached versus storage that is attached or detached as needed RAID JBOD Storage area network Network attached storageReferences edit eSata www serialata org Archived from the original on May 15 2009 Arsenal DAS Drives Retrieved from https en wikipedia org w index php title Direct attached storage amp oldid 1213058357, wikipedia, wiki, book, books, library,
