⊿ Point. {R} Glossary. ◢ Keyword: S. ▰ Sources. 〓 Books [B] ◥ University. {q} PhD. ⏫ THEMES. ⏫ Big Data. [B] Big Data. ⚫ USA. ↂ EndNote. ☝️ BD Dummies. SAN (storage-area network) A SAN does not provide file abstraction, only block-level operations. However, file systems built on top of SANs do provide file-level access, and are known as SAN filesystems or shared disk file systems. Storage[edit] Historically, data centers first created "islands" of SCSI disk arrays as direct-attached storage (DAS), each dedicated to an application, and visible as a number of "virtual hard drives" (i.e.
LUNs).[1] Essentially, a SAN consolidates such storage islands together using a high-speed network. Operating systems maintain their own file systems on their own dedicated, non-shared LUNs, as though they were local to themselves. If multiple systems were simply to attempt to share a LUN, these would interfere with each other and quickly corrupt the data. Any planned sharing of data on different computers within a LUN requires advanced solutions, such as SAN file systems or clustered computing. SAN compared to NAS[edit] SAN-NAS hybrid[edit] Hybrid using DAS, NAS and SAN technologies.