Storage area network (SAN) Storage:
Storage area network (SAN) is a secure high-speed data transfer network that provides access to consolidated block-level storage. An SAN makes a network of storage devices accessible to multiple servers. SAN devices appear to servers as attached drives, eliminating traditional network bottlenecks
SAN solutions are available as two types:
Both provide advantages based on business requirements.
The advantages of SAN include:
Network attached storage (NAS):
Network attached storage (NAS) is a dedicated server, also referred to as an appliance, used for file storage and sharing. NAS is a hard drive attached to a network, used for storage and accessed through an assigned network address. It acts as a server for file sharing but does not allow other services (like emails or authentication). It allows the addition of more storage space to available networks even when the system is shutdown during maintenance.
NAS is a complete system designed for heavy network systems, which may be processing millions of transactions per minute. NAS provides a widely supported storage system for any organization requiring a reliable network system.
Direct Attached Storage (DAS):
Direct Attached Storage (DAS) is a dedicated digital storage device attached directly to a server or PC via a cable. Advanced Technology Attachment (ATA), Serial Advanced Technology Attachment (SATA), eSATA, Small Computer System Interface (SCSI), Serial Attached SCSI (SAS), and Fiber Channel are the main protocols used for DAS connections.
DAS creates data islands, because data cannot be shared with other servers.
A typical DAS device may be an internal or external hard disk drive. Depending on data criticality, disk drives may be protected with different levels of Redundant Array of Independent (or Inexpensive) Disks (RAID). Modern DAS systems include integrated disk array controllers with advanced functionalities
DAS advantages include: