SCIENCE & ENGINEERING NEWS

San Diego, CA — Storage-over-IP technology promises to lower the cost of storage, particularly for small to midsize outfits, by using IP networks to link servers and clients to storage, eliminating the need for costly Fibre Channel infrastructures.

Adaptec Inc. is one the first vendors out of the gate, with its EtherStorage technology squarely aimed at the lower end of the soon-to-emerge storage-over-IP market. However, even in small to midsize networks, significant technical issues must be resolved before convergence can become a reality.

In a demonstration at Adaptec’s headquarters in Milpitas, Calif., eWeek Labs was impressed by the EtherStorage prototype, which networked standard off-the-shelf Ultra-3 SCSI drives to servers via a low-end NetGear Inc. switch and standard Gigabit and 100BaseT Ethernet network interface cards. The only component that wasn’t available off-the-shelf was a SCSI-to-IP bridge that was installed with the hard drives.

To create a similar configuration using current Fibre Channel SAN (storage area network) technology, an IT manager would have to buy Fibre Channel host bus adapters (for the servers), a Fibre Channel-to-SCSI bridge unit, a Fibre Channel hub and expensive Fibre Channel cable.

Current EtherStorage technology works in simple LAN implementations. When the technology becomes available in the second half of next year, IT managers will be able to run EtherStorage over WAN connections, Adaptec officials said. In addition to making off-site data replication a much easier task, this would greatly increase the range of SANs. Fibre Channel networks can range to a couple of kilometers, whereas IP networks could be worldwide, provided they got sufficient WAN support.

As with other nascent technologies, storage-over-IP solutions face major obstacles. Prospective customers must grapple with interoperability issues as well as latency and security concerns.

Interoperability (for hardware and software) looms as the largest hurdle for EtherStorage. Adaptec will have to develop partnerships with other storage vendors to ensure that customers can use both new and legacy storage products with EtherStorage bridges.

Adaptec must also convince SAN software manufacturers, such as Legato Systems Inc. and Veritas Inc., to port and support their Fibre Channel products for EtherStorage.

Latency is another big obstacle. Applications that rely on shared storage, such as Oracle Corp.’s Oracle Parallel Server, must be tested because the latency of EtherStorage and other storage-over-IP products is considerably longer than that of shared storage interfaces. As these technologies move onto WAN environments, latencies will become even longer, which could be a serious problem for distributed databases.

Security will also be a major issue as more storage traffic moves onto IP networks. Storage technologies such as SCSI and Fibre Channel assume that data is passed only to authorized partnersan assumption that is dangerous in IP networks.

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