The Treehouse Blog

No structure here… just some random goings-on:

For the last several kernel updates for FC4, my DVD sharing using GNBD hasn’t worked. I guess those special ioctl()s aren’t getting translated over or something. And NFS or SMB sharing an encrypted DVD just doesn’t do anything good at all (ignoring the fact that NFS seems really sucky with the latest FC4 updates). So, after months of not being able to watch DVDs, I gave up, and bought a USB drive cage to attach a DVD drive to Oak. Works perfectly. Despite performance issues and cabling evilness, I still can’t completely rule out a stack of USB drives RAIDed as a bulk storage solution, especially with all of the device mapper coolness in Linux. Too early to be thinking of that, though, as the computer storage fund hasn’t matured yet, despite the fact that Oak is at 99% capacity.

As Doug has mentioned, Asterisk and VoIP is still pretty neat. I’ve setup a teliax account, since they have pricing like nufone with a whole lot of rate centers worth of DIDs (they’re essentially a Level3 reseller). So, we just need to get some VPN’ing set up. I’m in desperate need of some UT, and I think VPN might be a useful substitute for a LAN party this winter.

My grandfather (on my Dad’s side) has been in the hospital on and off for more than a month now. Currently he has pneumonia, is very weak, and not entirely coherent. Your prayers would be appreciated for what could be a difficult Christmas season for the family.

Things at Ship are going fairly well. I did shoot myself in the foot with the “ip arp inspection” feature of the Sup720 this week though. Does 15 pps of ARP traffic seem like a good default threshold for shutting down trunk ports to you? Me neither. Of course, I asked that question after two ports had been err-disabled. Hopefully Tim and I will get to do a real test of some VMPS soon, too.

One of the things I wanted to take care of this summer was some type of outdoor lighting to be used when coming home at night. There just isn’t enough ambient light to figure out how to insert the key into the lock. I was considering LED lighting built into the deck, outdoor lights around the deck, and automating the existing outdoor lighting. Seeing this as an opportunity to finally begin playing with X10, I dove in.

The first phase was to control the deck and garage outside lights with a wireless remote. I purchased some X10 light dimmer switches to replace the light switches, a wireless transceiver, and a remote control. Everything worked well except the remote range seems a bit short. Latency wasn’t bad… probably a little less than a second.

Phase two involves the hall light, and a computer interface. I bought a PowerLinc USB and downloaded the WISH / x10dev software. The only “gotcha” for the software was that it assumes your hiddev0 is in /dev/usb whereas mine was in /dev. The error messages were not at all helpful in figuring that out, unfortunately. At this point the interface worked, but I had some phase issues: my two lights were on one phase, and the computer interface was on the other. Instead of building or buying a phase coupler, I went with Doug‘s suggestion of moving breakers around instead. They’re really about the easiest plug-and-play devices in existance, but it was something that I had never done before, so I certainly turned off the mains. My current unresolved issue is that the latency between issuing a command on the computer, and the device receiving the command, is aboud three seconds… way too long, especially if you want to do about six commands for a single event. Still haven’t figured out if this is as fast as the interface goes, or if there is a software bottleneck.

So, there’s my X10 project summary. I’m pretty happy with the results so far. It’s not incredibly cheap (I’ve spent about $100 to control three lights… albeit with a wireless remote and computer interface), but it has achieved the goal, and now I know a bit about X10

Since Oak has never had a DVD drive, and likely never will, I haven’t been able to play DVDs using MythTV. Unlike TV cards, MythTV has no means of sharing DVD drives between machines. Using GNBD (thanks to its inclusion in FC4) has given me the ability. GNBD works perfectly as advertised, however since the means of reading CSS keys from DVDs is apparently odd (ie, it generates errors), that part would not complete. For some reason, running mplayer on the machine with the DVD drive caches the data (apparently) allowing the remote mplayer to then play without difficulty. I demonstrated the process last night, and I scripted it tonight… ready to watch DVDs now! I had been going through Nemesis-decompression-scene withdrawal.

I’ve spent maybe 10 hours on this now (not all this week, mind you, but still). Getting WPA-PSK w/ TKIP certainly isn’t as easy as it should be, but that is probably entirely due to driver issues. Seems you can’t buy a great 802.11g card for Linux.

I had tried various versions of the Linux IPW2100 drivers, 1.1.0 most recently, and always ended up getting errors saying that the IPW_IOCTL_WPA_SUPPLICANT ioctl was not available. This is a symptom of a driver that doesn’t have the WPA support, but lsmod clearly showed the TKIP and other encryption-related modules loaded. Google suggested using the load and unload scripts provided with the driver, and to check the initrd for an old driver that might be overriding the freshly-compiled one. modinfo confirmed that the new drivers were getting loaded… still no luck. That’s where I was for a long time, retrying every once in awhile to see if anything was happier.

As it turns out, there is a problem in the way the drivers are compiled as modules which can be fixed with this patch (local cache). Keep in mind that the post I’m referencing here is only two weeks old… so, I’m probably not the only one having this issue. I’m somewhat amazed (and very happy) that Google has indexed it that fast.

Now, technically, that was enough to fix my problems. However, I spent the next 45 minutes or so trying to figure out why my connection would reset several seconds after coming up… which turned out to be another instance of wpa_supplicant in the background screwing things up. Tip: run one wpa_supplicant at a time.

The Mid-Atlantic ACM Regionals are now over. Looks like our team isn’t going on this year (you can see the whole results here). My teammates were complaining that problem ambiguity was partially to blame, but I’m not sure how that would be, given that all teams had the same set of problems.

I have Oak and Cedar upgraded to FC3 as well, now. NFSv4 is feeling happier regarding permissions mappings, however the particular reason I avoided NFSv4 in the past seems to still be present… Gnumeric locks up on saving a file to an NFSv4 share. I’ve worked around this by mounting that particular share with NFSv3 and everthing else with v4. Evolution also is a lot faster in FC3, however it is also uglier. I’m not a big fan of the Mac-like folder interface that leaves out the lines between folders that I’m so fond of.