Diskless boot makes it possible for computers to be operated without a local disk. The 'diskless' computer is connected to a hard drive over a network and boots up an operating system from a remotely located machine. iBoot is the convergence of the rapidly emerging iSCSI protocol with the Haifa Research Lab's recent progress in diskless boot technology.
Storage area networks (SANs) have been rapidly gaining popularity over traditional client-server configurations due to their ability to efficiently handle data. Typically, SANs require Fibre Channel, a specialized "fabric" or communication backbone. However, Fibre Channel is much more expensive than the standard IP (Internet Protocol) backbone that exists in nearly every enterprise. iSCSI, a new standard for storage networks, encapsulates standard SCSI (Small Computer System Interface) commands used to communicate with disks and transmits them over the existing IP network. Not only is iSCSI seen as a lower cost alternative to Fibre Channel, but is also expected to outperform Fibre Channel as Ethernet speeds jump from 100 Mb/sec to 1 Gb and 10 Gb in the near future.
Remote boot over iSCSI, or iBoot, pushes the iSCSI technology even further, opening the door to the exciting possibility of the diskless computer. iBoot technology allows a diskless boot of either Windows XP, Windows 2000, or the Linux operating system from an iSCSI target machine remotely located over a standard IP network. Although technologies such as Etherboot or Intel's PXE have already been used for diskless boot of Linux, these solutions were not transparent to the user. The entire booted operating system image was brought over to the diskless machine and retained in memory, without any possibility of permanently retaining changes made to the O/S kernel. Additionally, these technologies do not support remote booting of Windows.
iBoot overcomes these limitations and offers a seamless, diskless boot.
Eliminating the need for a local hard drive opens a wide range of possibilities for network management. Using this configuration, the disks for many network computers can be centrally managed, thereby facilitating backup, redundancy, and dynamic allocation of valuable storage resources while at the same time reducing cost to the enterprise.
The iBoot technology recently proved itself in a demonstration, booting a diskless machine in Haifa, Israel, off an iSCSI target machine near Seattle, and is currently being licensed to major companies.
Also, take a look at IBM's SAN Configuration utility for iSCSI Boot at http://alphaworks.ibm.com/tech/sancommander.