The iSCSI protocol has gained momentum as an alternative for Fibre Channel storage-area networks , and early adopters like it for the same reasons they like Ethernet – it’s inexpensive and easy to install.
The iSCSI protocol has gained momentum as an alternative for Fibre Channel storage-area networks , and early adopters like it for the same reasons they like Ethernet – it’s inexpensive and easy to install.
The idea behind iSCSI is to let users have universal access to storage devices and SANs over standard Ethernet-based TCP/IP networks. Approved by the Internet Engineering Task Force (IETF) as a standard in February, the protocol can be deployed effectively to host the traffic of Microsoft SQL databases, Exchange messaging or Oracle applications, users say.
Sean Wilde, director of global IS operations for Global Positioning System manufacturer Trimble Navigation in Sunnyvale, Calif., has just completed a beta test of iSCSI. He says that based on the results, that he’s ready to migrate his storage to iSCSI for its familiarity, cost and performance.
“The average Windows NT system engineer can spell SCSI, but not Fibre Channel,” Wilde says. “From my point of view, this is a technology that my technical staff is comfortable with and is competent to work with without any extensive training, unlike Fibre Channel. The iSCSI technology doesn’t breed any fear, uncertainty or doubt from the systems people.”
Wilde beta-tested three Adaptec iSCSI AHA-7211C adapters on three Windows NT servers. In his configuration, each server contained an iSCSI adapter that attached to iSCSI-enabled Network Appliance file servers via a Dell PowerConnect 5012 Gigabit Ethernet switch.
Over the course of this summer when Wilde can get some of his servers off-line for maintenance, he will migrate direct-attached storage from 125 Dell PowerEdge servers to Adaptec iSCSI adapters and Network Appliance file servers. He is looking to consolidate Oracle development databases on the file servers and eventually will put Oracle production and Microsoft Exchange data on the file servers.
Wilde can make a good business case for network-attached storage (NAS ) and iSCSI.
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“There’s a lot of churn and replication of the data and a lot of hand work – places where there’s manual intervention,” he says. “I want to use NAS, but I want something that performs very well – iSCSI seems to be the best fit at the best cost.”
While Wilde says he could implement his plans using NAS alone, he says that the performance he gets from iSCSI is far better.
“ISCSI gives me the high performance access to the file server at a fairly low protocol level,” Wilde says. “Our perception is that the performance is what we would get over a Gigabit Ethernet link.”
Storage insurance
Robert Filipovich, IT manager for Southern Insurance Underwriters in Alpharetta, Ga., says he had to make the same decisions for his storage data to replace his direct-attached storage – he needed to decide whether Fibre Channel, NAS or iSCSI would be best. He chose iSCSI for the traffic that Microsoft SQL Server and Exchange generate.
“The iSCSI protocol was very inexpensive as well as able to run over my current network,” Filipovich says. “It can give us large amounts of storage without having to spend the enormous amounts of money [vendors] charge for Fibre Channel.”
Filipovich uses a StoneFly Networks il500 Storage Concentrator to attach his Nexsan ATABoy 2.2 terabyte storage array to six of his servers. He uses Intel Pro1000 T adapters in his servers.
“Network traffic has grown to such a point that it’s cheaper to add Gigabit ports to the network than it is to add Fibre Channel ports. I probably saved 300% easy,” he says.
Filipovich’s reasons, plus compliance with an IETF standard and scalability, also sit well with Sterling Griffin, IT manager for the University of Alabama Pathology Department in Birmingham – enough to place his network backups on iSCSI.
“The basic reason we started looking at iSCSI or another type of [SAN] was backup,” Griffin says.
“Standard software and [hardware] was taking too long to back up. We started looking at our options. They were either a Fibre Channel SAN or iSCSI before it really was a standard. We said, ‘Let’s try this and see if it works,'” he says.
Griffin has 14 servers that are connected to Advanced Technology Attachment arrays from Promise Technology via Intel Pro1000 T IP Storage adapters and two SANRAD iSCSI V switches.
“We have four more servers on order, which will be added to the iSCSI network,” Griffin says. “We won’t be using any more local storage for the simple reason that right now I can add more disk space and attach them to the iSCSI switches.”
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