Sean's Blog

Dec 03

I was working in our new office this week. It has two gigabit Internet circuits. The speed test site couldn’t quite keep up…

I was working in our new office this week. It has two gigabit Internet circuits. The speed test site couldn’t quite keep up…

Nov 13

Never thought the Pope and Joe Paterno would have so much in common.

If he had been Father Sandusky, I’m guessing he would’ve had at least another 20 or 30 years before anything was done about it.

(Source: amplexushoc)

Nov 12

ben:

At MoMA

A SE/30 that still boots off a 100 MB Zip disk sits in my parents’ basement. One of the first computers I ever used.

ben:

At MoMA

A SE/30 that still boots off a 100 MB Zip disk sits in my parents’ basement. One of the first computers I ever used.

Oct 10

[video]

Oct 02

Dear Volkswagen

1. Could you please stop using triple square screws/fasteners all over the place? They’re a pain in the ass to work with, and difficult to find bits for. Tell your German friends too, please.

2. If you are going to continue to use triple square screws/fasteners, could you please not use friggin’ gorillas to tighten them up? When a caliper carrier is held in place by two 14mm triple square screws that are supposed to be torqued to 90 N-m, I should be able to easily break them free with a 18” breaker bar. And even if the breaker bar weren’t enough, PB Blaster and a rubber mallet should have been. But no, you just had to tighten the shit out of these things. Stop that shit!

3. If you are going to tighten the shit out of these screws, could you at least not put them in spots where it’s nearly impossible to get a bit and breaker bar on them? You know, the little things, like not putting the shocks, the springs, and the brake lines in just about every position you could get a breaker bar, or even a socket wrench in there?

4. Lastly, if you’re going to put nifty electronic sensors on the car to tell you when the pads are nearly worn completely, would you consider putting them on the axle that wears the fastest? It used to be the front, but these days, it seems to be the rear. Move the sensor there then.

It took me 15 minutes to jack up the car, pull the wheel, remove the caliper, and put new pads in. I spent hours (before loading up with new pads) trying to get the two 14mm triple square bolts off, so that I could pull the rotors. Ridiculous.

I love my GTI, but it really can be a pain in the ass to work on (which is probably true of most modern cars, to be perfectly fair, but still).

Sep 17

FCoE Woes

We’re building out a few new datacenters at work now, and before I can get a start on the Linux infrastructure, we’ve been working on the core infrastructure (network and SAN). We’re fortunate in that we’re able to use some of the latest-and-greatest technologies, including some nice new 10GigE switches that support FCoE, along with necessary CNAs (converged network adapters).

What makes these really cool is your NICs and HBAs are now one in the same. For a given level of redundancy and bandwidth, your port count is cut in half. And with these fancy Twinax cables/transceivers you can get, you don’t need to use fiber to leverage these benefits.

Of course, nothing’s perfect. I haven’t been working on the networking side of things too much, but it looks like it’s been quite a pain to architect the design of what will be a truly converged network, with a pair of switches providing redundant network and fabric connectivity to the SAN (requiring things like VPCs, etc.).

Among the things I’ve noticed is the difficulty of getting the NIC side of the CNA bonded on Linux. Let’s say you configure a switch from a certain vendor whose name rhymes with Crisco such that you have “channel-group XXX mode on” for each port. Great. You can boot from SAN just fine, and all the stuff on the FC side works just fine. But no networking. OK, you figure. Let’s try “channel-group XXX mode active” on each switch port, and then configure LACP on each host. Yeah, don’t do that. It’ll get networking going, but it’ll break FCoE connectivity, which especially sucks when your OS volume(s) are stored on the SAN.

As best as I can figure it, no CNA on the market today (and perhaps the FCoE standard itself) allows for LACP to be configured at the adapter level. Naturally, my first thought was to try active/passive bonding at the Linux level instead, but that didn’t work. Inexplicably, a vendor suggested we try XOR load balancing (mode=3 when you load the bonding module), and that managed to get things working.

As nice as it is to cut your necessary port count in half, it’s kind of scary when you’re putting everything (network and storage) in one bucket. Especially when the documentation hasn’t quite caught up to the technology.

Sep 14

I like the plate. Well chosen usage of six ASCII characters.

I like the plate. Well chosen usage of six ASCII characters.

Aug 21

[video]

[video]

Aug 18

A Week With A Mustang

A good friend of mine was getting married in California (in the Monterey area, to be exact), and being the car nut I am, I couldn’t pass up the opportunity to visit and terrorize the PCH. But since I was flying out, I would need a suitable rental car to do it in. In poking around the various rental sites, a BMW was looking to be the best option (at a reasonable price, anyway), but by the time I was actually ready to book it, it was an option no more.

The second best alternative actually appeared to be a Mustang, of all cars. As much as I love small, light, agile cars over the muscle car type, Mustangs have gotten so much praise for being fun to drive lately, and I figured “hey, what the hell.” So, I booked a Mustang V6, and hoped I’d at least get one with the newer 300 HP engine, instead of the 210 HP slug.

And then I get to the rental counter. “Sir, would you like to upgrade to a GT for $10 per day?” You might as well ask me if I’d like to date Adriana Lima. And even better, I got a nearly-new one, with the 5.0 liter V8, and only 2,000 miles on the odometer. It had a terrific sound on startup, but in pulling out and navigating the garage at SFO, it felt big and heavy (especially compared to my GTI). Had I made the wrong choice? Was this going to suck on the PCH?

No, and no. Emphatic nos. Yeah, it’s a bit big and heavy compared to what I prefer, but the more you drive it, the smaller it feels. The harder you push it, the more agile it feels. And taking it down the PCH from Monterey to right around Big Sur was an experience I’ll never forget (ahem, with stability control inexplicably turned off). Had there not been other constraints (you know, like a wedding), I would have gone much further, and Avis would be wondering how a car with so few miles could have tires so well worn. It was that much fun.

OK, so the automatic sucked (good luck finding a rental place in the US that’ll give you stick without charging an arm and leg, which is a bit ironic, since you’d need both to drive it, but I digress), and the gas mileage was about what you’d expect it to be, but it was still buckets of fun. I honestly don’t know if I’d ever get one myself, but it’s something I’d definitely look at—and I never in a million years thought I’d say that about any Mustang. Well done Ford, well done.