Technology
An overview of the technology of RAID system host connectivity, and SAN integration.
|
SME
SME Interfaces: USB, Firewire, eSATA
USB
USB 2.0 is the most widely used interface and works well on the desktop, with a maximum transfer rate of 480 Mb/s. It is also backwards compatible with USB 1.1, but with a much slower transfer rate.
Firewire
FireWire 400 (also known as IEEE 1394a) has a maximum transfer rate of 400MB/s and so competes on the desktop with USB 2.0, although it is possible to daisy-chain devices over a longer bus length. Firewire 800 (also known as IEEE 1394b) doubles the maximum possible transfer rate, and currently leads USB 2.0 for transferring large amounts of data, such as Audio and Video professionals.
eSATA
The eSATA connection is relatively new. It is not merely an external version of the SATA connection because it uses a different cable connector and offers doubles the maximum possible bus length. With a maximum transfer rate 3 Gb/s eSATA far exceeds what is possible with USB FireWire, but it does require its own power connector. However, it is an excellent choice for external disk storage.
Related Products
PCIe-C
PCIe-C: PCIe over Cable
Conventional PCI became the standard IO bus during the 1990s, and was followed by newer versions such as PCI-x and PCI-x 2. PCI Express (PCIe) was developed as a serial connection to provide scalable point-to-point connections while maintaining software compatibility with conventional PCI, and has now become a defacto standard. The Peripheral Component Interconnect Special Interest Group approved the standard for PCIe over Cable in 2007.
PCIe-C as a single hosted DAS solution offers many options and advantages over the other available technologies. The obvious performance and cost benefits should make this technology high on anyone's selection list. The other options include front end expansion using a PCIe switch and back-end expansion via a SAS bus to JBODs or further RAID systems.
Related Products
RAIDFLEX-47T08pe PCIe-C 8-bay Tower RAID
RAIDFLEX-47208pe PCIe-C 8-bay 2U RAID
RAIDFLEX-SW-47100pe 1U 9-port Switch
Downloads
PCIe-C White Paper (to be added shortly)
iSCSI
iSCSI: Internet SCSI
The iSCSI protocol allows clients (called initiators) to send SCSI commands (CDBs) to SCSI storage devices (targets) on remote servers. It is a popular Storage Area Network (SAN) protocol, allowing organizations to consolidate storage into data center storage arrays while providing hosts (such as database and web servers) with the illusion of locally-attached disks. Unlike Fibre Channel, which requires special-purpose cabling, iSCSI can be run over long distances using existing network infrastructure.
Related Products
RAIDFLEX C6000
NAS
NAS: Network Attached Storage
Network-attached storage (NAS) is file-level computer data storage connected to a computer network providing data access to heterogeneous network clients, rather than directly being connected to the computer.NAS devices enable multiple computers to share the same storage space at the same time. These devices are assigned an IP address and can then be accessed by clients (PCs or laptops) via a server, which is within the NAS device (NAS devices are often referred to as NAS servers ) that acts as a gateway to the data.
Some of the big benefits of NAS include the expandability; if more storage space is required, simply add another NAS device and expand the available storage. NAS also brings an extra level of fault tolerance to the network. Fault tolerant measures such as RAID can be used to make sure that the NAS device does not become a point of failure. NAS systems often contain more than one hard disk drive, often arranged into logical, redundant storage containers or RAID arrays for added redundancy/security - thus protecting data in the case of disk failure.
Related Products
RAIDFLEX C6000
SAS
SAS: Serial Attached SCSI
Serial Attached SCSI (SAS) is a data transfer technology designed to move data to and from computer storage devices such as hard drives and tape drives. It is a point-to-point serial protocol that replaces the parallel SCSI bus technology, and uses the standard SCSI command set. At present it is slightly slower than the final parallel SCSI implementation, but in 2009 it will double its present speed to 6 Gbit/s, allowing for much higher speed data transfers than previously available. It is 'downwards-compatible' with second generation SATA drives. (SATA 3.0 Gbit/s drives may be connected to SAS backplanes, but not vice-versa.)
Related Products
FC
Fibre Channel
Fibre Channel is a highly-reliable, gigabit interconnect technology which allows concurrent communications among workstations, mainframes, servers, data storage systems, and other peripherals using SCSI and IP protocols. It provides interconnect systems for multiple topologies that can scale to a total system bandwidth on the order of a terabit per second. Fibre Channel delivers a new level of reliability and throughput. Switches, hubs, storage systems, storage devices, and adapters are among the products that are on the market today, providing the ability to implement a total system solution.
Related Products
