Instant iSCSI By Open-E
Open-E's iSCSI product can be called "iSCSI-on-a-chip," as it integrates an UltraATA interface with the integrated Linux-based software that is stored on a flash memory component.
Storage companies have maintained the same thing now for almost three years: Direct attached storage (DAS) is inflexible and creates bottlenecks, while its administration is time consuming. The future of professional storage, they say, belongs to networked appliances that allow placing storage units anywhere within your network. Switching to iSCSI will thus take storage to the next level, they say.
So if iSCSI really is that good, why has it not taken off yet? In addition to the high price of Fibre Channel infrastructures that are required for high-performance applications, technical barriers remain. A look at iSCSI in detail and its evolution accounts for the protocol's limited adoption.
iSCSI is a shortcut for Internet SCSI, in which SCSI stands for the small computer system interface that is the predominant DAS storage interface in the professional space.
The iSCSI protocol is used to encapsulate native storage data into IP packages, which in turn allows for transferring this data over existing networks as if these were a local storage interface such as UltraSCSI. Due to the large variety of IP networks (PAN, WLAN, LAN by means of Ethernet or Fibre Channel, WAN, MAN and the Internet), a storage area network (SAN) based on the iSCSI protocol can technically bridge any distance, and it is only limited by the performance of the particular network(s) it uses.
Knowing this, it becomes obvious that a SAN is typically kept within the limits of a fast network neighborhood, which brings us back to the barriers we mentioned: Storage devices that respond to multiple client requests require adequate bandwidth to do so. A 100 Mbit Ethernet network, for example, is technically capable of hosting iSCSI, but its performance would not really be up to task. Fibre channel, on the opposite end of the spectrum, often is too expensive for small- and medium-sized businesses.
The rapid deployment of gigabit Ethernet (GbE), however, gradually creates a substantial backbone for iSCSI applications. Although GbE over fiber cable is the state-of-the-art solution, we estimate that GbE over copper wire networks will further accelerate the transition from direct attached storage to storage area network applications; this type of infrastructure is also backwards compatibility and is available at an attractive price point.
