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Cisco Gives iSCSI the Network Boot

Ever wish you could boot servers directly from your IP network instead of having to call someone to do it manually?

Cisco Systems Tuesday answered that call with the release of "Network Boot" - a new feature for its Cisco SN 5400 Storage Router portfolio it says continues the recent trend using iSCSI networking in new and innovative ways.

The San Jose, Calif.-based computer-networking equipment maker said the feature essentially lets users consolidate the system drive or "booting" functions from dozens of servers onto an external storage device (such as a disk subsystem) and access these servers directly from the network.

The add-on feature is now available through the latest firmware upgrade for both the Cisco SN 5420 and Cisco SN 5428. The company said it would also be available for the Cisco MDS 9000 Family. Cisco said customers with older versions of the firmware could now download the new version for free.

Veritest, the exclusive provider of third-party independent testing for the Microsoft Certified for Windows program, Tuesday also said that based on its recent testing, Network Boot met the certification requirements for Microsoft Windows 2000 Server, for supported hardware environments. To use Network Boot, Cisco SN 5400 customers must first have servers that have installed Cisco's iSCSI drivers for Microsoft Windows 2000 operating system.

The servers must also support Preboot eXecution Environment (PXE), a standard defined by Intel for remote booting and systems startup. Servers that do not currently support PXE can still use network boot in conjunction with standard Ethernet network interface cards such as Intel PRO/1000 MT Server Adapters.

"Intel supports Cisco's open-standard approach to Network Boot, which further enhances the advantages of iSCSI," said Tim Dunn, general manager of Intel's LAN Access Division. "Used with any Intel PRO/1000 MT Server Adapter, Network Boot provides a cost-efficient solution required by today's IT professionals who need to easily and reliably manage growing quantities of stored data."

The company said Network Boot should also make life easier for customers using densely clustered servers such as the 1 or 2U rack-mounted server appliances or the even blade servers, which are housed closer together.

Cisco said in addition to saving time and money, customers could also easily upgrade all servers to the most up-to-date versions of software from one central location.

How iSCSI Works
When an end user or application sends a request, the operating system generates the appropriate SCSI commands and data request, which then go through encapsulation and, if necessary, encryption procedures. A packet header is added before the resulting IP packets are transmitted over an Ethernet connection.

When a packet is received, it is decrypted (if it was encrypted before transmission), and disassembled, separating the SCSI commands and request. The SCSI commands are sent on to the SCSI controller, and from there to the SCSI storage device. Because iSCSI is bi-directional, the protocol can also be used to return data in response to the original request.

iSCSI is one of two main approaches to storage data transmission over IP networks; the other method, Fibre Channel over IP (FCIP), translates Fibre Channel control codes and data into IP packets for transmission between geographically distant Fibre Channel SANs. FCIP (also known as Fibre Channel tunneling or storage tunneling) can only be used in conjunction with Fibre Channel technology; in comparison, iSCSI can run over existing Ethernet networks.

A number of vendors, including Cisco, IBM, and Nishan have introduced iSCSI-based products (such as switches and routers).