Advanced Digital Information Corporation has launched
iSCSI add-ons for its Scalar 24 and Scalar 100 models, allowing
servers to connect to a library over Ethernet.
"We think now is a good time because the iSCSI standard was
ratified about a year ago, so you don't see compatibility issues
with other vendor's products," said Adic product marketing manager
Sandra Adelberger. "Microsoft is building iSCSI into Windows
2003."
Backup consolidation previously required a storage area
network with Fibre Channel server adapters, network switches and
management expertise. Adelberger acknowledged that iSCSI is lower
performance than Fibre Channel, but said that it has the advantage
of re-using the existing Ethernet infrastructure and skills.
"I think many companies like the idea of a San but haven't done
it because of the cost - not just the component cost, but the cost
of know-how too. Not only do you need a consultant to build the San
but then you have to maintain it," she said.
As with backup consolidation over Fibre Channel, the iSCSI route
requires the backup software to support shared storage. Each server
sees the library as if it were attached directly, so one server in
the network must be designated as master. However, it only controls
access to the library, and does not route data.
Adelberger said iSCSI requires an extra $4,000-$5,000 protocol
conversion module in the library. She compared this with the TCP/IP
offload engines (Toes) that can be added to busy servers to offload
the job of processing iSCSI data packets.
Adic is the biggest tape library developer to take iSCSI on
board, but it is not the first. Spectra Logic has offered iSCSI
libraries since last May, and sold Gigabit Ethernet-attached
libraries before that.
However, Mike Sausa, Spectra Logic's regional sales director for
central Europe, agreed that now could be a good time to enter the
iSCSI market. He said that although iSCSI had generated lots of
interest for Spectra Logic, it has not been a big seller so
far.
He added that what's important is how well integrated iSCSI is
with the rest of the library. "Ours is fully integrated, but I
understand ADIC uses a third-party bridge device," he said.
Bryan Betts writes for Techworld.com