Get the basics of enterprise-level storage
In its simplest terms, storage refers to a device that houses data. There are many different ways to categorize a storage device.
By storage Architecture
- Direct attach storage (DAS) refers to a storage system directly attached to a server, without a storage network in between.
- Network attached storage (NAS) is a specialized storage server with its own IP address that is made available to multiple clients and servers on a local area network (LAN) or wide area network (WAN).
- Storage area network (SAN) is a network of shared storage devices, such as disk storage arrays and tape systems. The architecture of a SAN is such that storage resources are made available to multiple servers on a local or wide area network.
By network protocol
- The Internet Protocol Suite (TCP/IP) is the set of communications protocols used for the internet and other similar networks. TCP/IP over Ethernet is the medium traditionally used for NAS.
- The Fibre Channel Protocol (FCP) transports SCSI commands over Fibre Channel networks.
- The Internet SCSI (iSCSI) protocol enables servers to send SCSI commands to SCSI storage devices. Unlike Fibre Channel, which requires special-purpose cabling, iSCSI only requires standard Ethernet to traverse LAN and WAN infrastructures. It is a SAN protocol that businesses of all sizes are adopting at a high rate.
By storage file system
- File-level storage refers to data organized in a file system. To the client, the data would be represented as individual files, such as a Microsoft® Word document. NAS platforms, such as the Dell™ PowerVault™ NX family, use file-level storage.
- Block-level storage converts data into a sequence of fixed-length bytes or bits (that is, a block), leaving to attached systems the task of managing the raw data. SANs, such as the EqualLogic™ PS Series (Em inglês), use block-level storage.
- Object-based storage organizes data into flexible-sized data containers called objects. Each object has both data (an uninterpreted sequence of bytes) and metadata (an extensible set of attributes describing the object). The Dell DX Object Storage Platform uses object-based storage.