Network-attached storage

[2] For example, some NAS versions of drives support a command extension to allow extended error recovery to be disabled.

In a non-RAID application, it may be important for a disk drive to go to great lengths to successfully read a problematic storage block, even if it takes several seconds.

NAS is generally not as customizable in terms of hardware (CPU, memory, storage components) or low level software (extensions, plug-ins, additional protocols) but most NAS solutions will include the option to install a wide array of software applications to allow better configuration of the system or to include other capabilities outside of storage (like video surveillance, virtualization, media, etc).

DAS typically is focused solely on data storage but capabilities can be available based on specific vendor options.

SAN protocols include Fibre Channel, iSCSI, ATA over Ethernet (AoE) and HyperSCSI.

A shared disk file system can also be run on top of a SAN to provide filesystem services.

A group of Auspex engineers split away in the early 1990s to create the integrated NetApp FAS, which supported both the Windows SMB and the UNIX NFS protocols and had superior scalability and ease of deployment.

The first type of NAS is focused on consumer needs with lower-cost options that typically support 1–5 hot plug hard drives.

The second is focused on small-to-medium-sized businesses – these NAS solutions range from 2–24+ hard drives and are typically offered in tower or rackmount form factors.

years, offering flexible network-based storage to the home consumer market for little more than the cost of a regular USB or FireWire external hard disk.

Many of these home consumer devices are built around ARM, x86 or MIPS processors running an embedded Linux operating system.

PBBAs typically include data deduplication, compression, RAID 6 or other redundant hardware components, and automated maintenance.

These are designed to be easy to set up on commodity PC hardware, and are typically configured using a web browser.

Network-attached secure disks (NASD) is 1997–2001 research project of Carnegie Mellon University, with the goal of providing cost-effective scalable storage bandwidth.

The File Manager provides a time-limited cachable capability for clients to access the storage objects.