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…

Bose Headphone Repair

I have a pair of Bose Reality-Cancelling Headphones – not too effective against human voices, but they do a good job of cancelling steady noises like air conditioners and computer fans. I like them well enough, but I wouldn’t recommend them anymore.  Maybe the Panasonic version?

The problem is that after five years or so, the pads that go over the outside of my ear have started to come apart at a seam, exposing the foam. The solution is simple, of course: sew them back together. The hard part is the lack of room to work. I cut off a sewing needle to roughly 3/8″ and ground it back to a point. Surgical forceps work well to hold the seam back together temporarily, then a pair of long-nose pliers is what it takes to jam the short little needle through. I ending up using a second pair of forceps as an anvil and as as extra set of fingernails to grab the needle when it comes through. I didn’t even attempt any kind of running stitch or fancy lacing/trussing/macrame, I just tied off each stitch as I completed it and moved on to the next one.

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Now, the failure is running around the inside of the cushion – when I repair one section, another one pops loose.  Pretty soon I will have sewn all the way around, and shortly after that I suspect the material will simply fail entirely.  At that point, I don’t know.  I’ve been known to limp stuff along just for fun.

Current score:  Patience vs Rampant Consumerism: 1-0.

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The Knucklewarmer

You ever have this happen to you? There you are, working away in your secret underground laboratory, trying to be a good citizen of the earth. You have the heat turned down to an environmentally-responsible way chilly, and your hands are freezing. Happens to me every winter. It also happens to my colleague Dan Bedard, who thought “Gee, I should just make something to redirect all the warm air coming from my computer so it blows over the keyboard!”

Well, that’s a good idea, Dan. So good, in fact, I’m stealing it.

Behold the Knucklewarmer. Made from genuine earth-friendly recycled junk mail, it catches the warm air venting from the side of my rusty-but-trusty Thinkpad and directs it over the keyboard. 2.13 GHz of Pentium M goodness makes enough warmth to keep the knuckles working and to maintain feeling in my fingertips. Not bad for a laptop.

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What about those newer laptops? What about even, God forbid, a netbook? No problem. Sure, an Atom N270 is something like a sub-5-watt part, but have no fear. The chipset uses another 9, and together they’ll keep ice crystals from forming. This baby works pretty well on a Dell Latitude 2100 netbook.

Construction is simplicity itself, as should be obvious from the pictures. It’s pretty much (1) locate some junk mail, (2) cut it to shape to form a little piece of ductwork, and (3) tape it up and slide it into position. More complicated versions are left as an exercise for the reader.

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Downside? My next main machine was a MacBook Pro, and this didn’t work with the milled aluminum monoblock of desire. The heat comes out of that one from under the display hinge. No problem, though, because after that I switched back to a Thinkpad (both run Linux full time, by the way) and I’ll have heat to spare this winter.

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Welcome…

I’ve made a few things and hacked a few things over the years, but my documentation was scattershot at best.  This blog should serve as a central place to record them, mostly for my own reference.  On the other hand, you’re reading it, so “Welcome”.  I hope something will be useful.

 

Now for a flurry of copying stuff over to here…