Monthly Archives: November 2014

Installing thick (15mm) 2.5″ drives in Dell drive carriers

I have a bunch of Dell 1955 blades that I’m reconfiguring. They used to be a fairly garden-variety supercomputer – 530 blades, Infiniband network, made it onto the Top500 list in 2006 (UNC’s “Topsail” cluster). Topsail reached the end of its usable life for that sort of workload (how progress does march on, no?) and was headed to surplus. The group I work in at Renci intercepted it and turned it into a Big Data cluster. The first-generation Nehalem cores aren’t so hot anymore, but having 1060 SATA channels for running Hadoop on… dude! You’re resurrecting a dell!

The only real hitch was storage. The blades came with 40 gig disk drives – enough to hold a boot image and not a whole lot more. The machine is long out of maintenance at this point, and the biggest drive Dell ever officially supported in there was probably a 300 gig part, so off to third-party land we go. I scored a couple of Hitachi 750 gig drives a year ago and they worked great. Now, Western Digital has started volume shipments of their 2TB 2.5″ drive. Naturally I ordered a pair of those.

Best laid plans, etc. When I went to install them in the Dell carriers (with the 40gig drives removed), there was a slight clearance problem The metal corner brace gets in the way of letting the drive fully seat, so the fourth mounting hole doesn’t line up with the drive:

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…so it’s off to the Secret Underground Laboratory. Fortunately, the carriers are cast out of zinc, rather then being made out of steel, so they’re really quite easy to modify. I cut away some of the corner bracing of the first one with a Dremel tool, but that took about fifteen minutes. I have 530 of these to do, so I want something a lot faster.

Jamie would use a tablesaw and face shield, but I decided to go with something a slightly more subtle. I grabbed my total-piece-o-junk Jorgensen mitre box – never buy one of these, folks. The cast bed comes from the factory out of true, and if you have to pay a machine shop to resurface it, well, it’s cheaper to buy a good one.

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Which is why I don’t mind using it to cut metal. I hate that tool, I want it dead so I can throw it away. You understand.

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Once you have a nice notch all the way down to the side rail, just grab the rail with one pair of pliers and the excess tab with another, and twist. The zinc will fail right where it should. Clean up the burrs with a file, and you’re in business.

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Then install the drive in the carrier, the carrier in the blade, the blade in the bladecenter, and let Rocks reinstall Linux on it over the network.

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Now I just need to do this 527 more times…

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