May 15th '13 7:34

September 14th '12 9:12

pgenera@love:~$ dmesg
[24009481.872712] Clock: inserting leap second 23:59:60 UTC

November 16th '11 18:22

It sure impresses me how long I can leave this thing alone for and still have it be working when I come back. I just went through the (oddly trivial) process of switching from master/slave replication to synchronous for the backend of this site, and it was trivial. Now to fix up the image-importer thingy and then, you know, write stuff ever.

By the by, if you have more data than will fit in a single RDBMS and you're not looking at Google's BigQuery right now, you really should be. It is amazingly hot shit.

June 23rd '11 7:14

April 29th '11 20:45

Two interesting bits of real-world authentication - or lack thereof - came across my bow this morning.

First, the CA DMV. In California, you can get a DMV appointment, which means you only wait half an hour to get your essential government service, instead of an hour and a half. Awesome, right? Except the next appointment is usually a month away. I've always been a good citizen, making my appointments, waiting patiently, and getting my registration done a few weeks after the legal deadline (10 days for used vehicle purchases).

Here's the thing though - if you seem like you know what you're doing, you don't have to prove you have an appointment. So you can go to the DMV whenever you want, stand in the appointments only line, and say you have an appointment for whatever the upcoming even-10-minutes time is, and bob's your uncle. If you seem confused or don't speak english, they'll want to see a printout of your appointment confirmation email, which is also easily faked. I'm not sure why I didn't think of this before. Proceed at your own risk, of course.

My second errand today was to get some keys copied. There's a great key show down the street from my house, so I stopped off on my way home from the DMV and asked if he could copy the key for my truck. This is an early chipped key, so there's a bit of RFID happening and you have to 'program' the vehicle to recognize the key. Normally this is done by using two already-working keys, and talking to the ECU by doing things with the keyless entry keypad. If you don't have two working keys (as I didn't), you have to connect a programmer to the OBD-II port and instruct the ECU to look for a new key. And before the ECU will do anything, a 10 minute timer has to expire.

I thought this was really weird at first - two keys to program it? 10 minutes to read a value and store it in NVRAM? What the what? - but its actually a pretty decent design. If you could program new keys with just one key, valets could readily steal cars. If all you needed was to talk to the ECU for a few seconds to program a new key, anyone with a key impression and some minor electronics knowledge could make off with the car handily. The delay helps out as much as is probably reasonable. Of course, none of this addresses the (probably super trivial) walk-by cloning that's possible today, but hey, it was almost 20 years ago when this stuff was designed.

April 15th '11 23:37

Dear everyone I know,
I haven't left yet for the mission trip. I don't know why y'all think I have, but I haven't.

Of course, by the time you read this, I will have. So there; you don't have any more information than you did before.

March 8th '11 20:48

January 6th '11 20:45

You see that last entry? About my complicated flights? I just thought everyone should know that I got well and truly boned by mother nature on that one. Christ.

December 23rd '10 20:45

In the grand tradition of living a complicated life, here's where I'll be for the next few days:

12/23: SJC -> ORD -> LGA
12/24: LGA -> Grand Central (1am) -> MetroNorth -> New Haven -> daddy -> Guilford
12/25: santa.
12/26: Guilford.
12/27: New Haven -> Grand Central -> Subway -> JFK -> LAX -> SFO
12/28: SFO -> LAX
12/29: Joey gets married!
12/30: LAX -> SFO
12/31 -> 1/2: nap time.

If you are in any of those places and think you can leap on me as I run from one place to the next, you are damn well welcome to try, bitches.

Merry Christmas. Happy Gate Rape.

December 19th '10 21:46

December 13th '10 23:49

I added two disks to my Very Large Video Storage Array this weekend, because I had them laying around and I thought it would be fun. This machine is a kirkwood-based arm5 running Debian Squeeze (a marvell open-rd client, to be specific). The reshape caused the overall storage capacity to go from ~1.2TB to ~2.1TB. I added the discs, started the reshape, and went to bed.

A few hours later, something stupid happened to the electricity in my garage and all my stuff got turned off. I fixed that, got everything turned back on, and went to check on the reshape. The kernel was complaining that the reshape wasn't far enough along to be automatically restarted, which was scary and seemed untrue. I emailed the linux-raid mailing list and talked to the maintainer a bit, and he seemed to think it was an overflow on arm specifically of the kernel code that performs this check.

Neil was right; when I eventually got a sufficiently modern version of mdadm running on an x86 machine, I was able to re-assemble the array and get it reshaping again. A few false starts later (I may have slightly unplugged the disks from the laptop while checking on it last night), the reshape completed successfully, I reattached the disks to the arm machine, and was able to extend the underlying ext4 partition without error. I've verified all the (important) data against checksums and backups, and there appears to be no lasting damage.

While this failure was due to the overall complexity of my storage system, it highlights the advantages of linux software raid: I was able to trivially move the disks to another machine to perform recovery and work around hardware-specific bugs.

October 27th '10 1:14

October 25th '10 19:13

October 25th '10 17:13

October 19th '10 9:09

October 18th '10 6:13

I'm not really certain how that happened! I'm in Tokyo (Roppongi? Something I can't pronounce or spell) with Alycia right now. I'm working, she's off having fun, and the city is generally unusual and confusing.

I was expecting more culture shock, as in Beijing last year. Beijing had such a feel of being recently first-world - you never were sure how to get somewhere or what to do. The cabbies didn't seem to know how to get around either. Most of this difference is probably really due to currency - since everything is expensive here, especially compared to China, we've been taking fewer cabs.

Having a cell phone that works, with data, is fantastic. Google maps makes travelling 100% less scary for me - I know I can walk a long way, and having the phone means knowing which way that is. The rental SIM is pretty ridiculously expensive though - $220 for the week - but at least I'm not paying. Network speeds are pleasantly stupidly fast as well.

The only thing that's freaking me out is there are basically no coffee shops. I sort of expected a tea-based hot beverage society, but there's a lot of coffee, and it all seems to come out of vending machines. I think I'd prefer tea.

Photos to come. Jet lag is a real thing and pretty annoying.