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Cracking the iSCSI conundrum

Posted on 5 Mar 2010 at 17:09

Steve Cassidy battles to get his iSCSI setup working properly

Join with me please in extended contemplation of the backside pictured to the left. This box is the Dell EqualLogic PS4000, and I won’t be trying to take any prettier pictures of it because, in fact, it doesn’t have any prettier angles.

There are a couple of reasons for that: for one it’s an iSCSI disk farm, and one box of disks tends to look very like another box of disks. And anyway, in this case the small portion of the rear of the case that I shot is all we need to consider.

It’s the part that presents two rows of Ethernet connectors, the part we have to work with, the part that makes the vital difference between rational and sensible deployment of a large, expensive, high-performance bit of kit – or, on the other hand, a disaster of staggering proportions...

Are the stakes really that high for a humble box of disks? You bet they are, because what we’re talking about here is iSCSI. Back in the high summer of 2009, Dell put on a show to talk about getting its range of 11th-generation servers rolling, and it brought along a User-Ambassador kind of guy from a firm of lawyers who was only too pleased to talk about what he was doing with these newer, faster, whizzier servers.

In the course of that chat he let slip that the key to his successful upgrade lay in migrating away from an iSCSI setup by Adaptec, and onto Fibre Channel to link up his farm of virtual machines. The heavy-metal specialist journalists and analysts in the audience smelled a story here, and Dell’s guys began to look a little uncomfortable: after all, the company does offer a range of bits and pieces for implementing iSCSI into its wider Dell product portfolio.

Adaptec is a name I haven’t been seeing much of late, and since that company appears to have lost its focus when dealing with the market you and I inhabit as small business networkers, I’m not all that bothered by hearing about its woes

Personally, I wasn’t too worried by his frank admission of failure. For one thing, Adaptec is a name I haven’t been seeing much of late, and since that company appears to have lost its focus when dealing with the market you and I inhabit as small business networkers, I’m not all that bothered by hearing about its woes in a far larger marketplace.

Rather more significant was the fact that lots of people seemed to be getting into, and then rapidly out of, this whole idea that they can use iSCSI as a step up for their storage capability. In other words, by last summer this was already widely known to be more than just an Adaptec-specific problem – iSCSI is a platform that starts out looking easy and finishes up being difficult.

I therefore decided to abuse my position, by choosing my time to pursue the Dell team mercilessly: I watched their faces during this briefing, and I knew that the more useful half of the story would come – not from putting Adaptec in the pillory and chasing Mr User-Ambassador Guy. The right answer was lurking somewhere, and that’s always going to be more interesting than sneering about the wrong answers everyone else has been trying and failing with in private.

My basic idea was to put together the pile of kit that’s rarely reviewed as a whole, the set of parts that would be sold to a mid-sized operation (with an unlimited budget) to make iSCSI fly. I figured this might show up how the manufacturers want this technology to be used, which is quite different from the way people actually use it in the real world.

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