Shallow Thoughts : : Jul

Akkana's Musings on Open Source Computing and Technology, Science, and Nature.

Sat, 30 Jul 2005

"I'm sorry, Dave, but I can't let you have your disk back"

I got a new, large, and most important, quiet disk for my laptop.

The first Linux distro I installed on it was Ubuntu. Since quiet was my biggest incentive for buying this disk (the old IBM disk was so loud that I was embarassed to run the laptop in meetings), as soon as the install was finished I carried the laptop into a quiet room to listen to the disk,

Turns out it was making a faint beep-beep noise every second or two, plus some clicking in between.

Another, non-Linux, operating system installed on the same disk does not make these beeping or clicking noises. It was clearly something Ubuntu was doing.

After a long series of ps and kill, I finally narrowed the problem down to hald. HAL is polling my disk, once per second or so, in a way that makes it beep and click.

(HAL, if you're not familiar with it, is the Hardware Access Layer which works hand in hand with the kernel service udev to monitor hardware as it comes and goes. No one seems to know where the dividing line is between udev and hal, or between the daemons udevd and hald. Most systems which enable one, enable both.)

I floated down to the control room to dismantle HAL, humming "Daisy".

But it turned out I didn't need to kill HAL entirely. The polling apparently comes from HAL's attempt to query the CDROM to see if anything has been inserted. (Even if there is no CDROM connected to the machine. Go figure!)

The solution is to edit /etc/hal/hald.conf, and change true to false under <storage_media_check_enabled> and <storage_automount_enabled_hint>. This changes hald from a "blacklist" policy, where everything is polled unless you blacklist it, to a "whitelist" policy, where nothing is polled unless you whitelist it. Voila! No more polling the disk, and no more beepy-clicky noises. I suspect my drive will last longer and eat less battery power, too.

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[ 20:00 Jul 30, 2005    More linux | permalink to this entry | ]

Fri, 29 Jul 2005

Switching from Debian to Ubuntu; Dependencies To Build GIMP

I've switched my desktop machine from straight Debian (unstable, or "sid") to Ubuntu "Hoary Hedgehog". Sid was just getting too unstable for me (I'd been spoiled because it really has been pretty stable, except for printing problems, for the past few years). Freetype now has rendering problems, so any fixed width terminal font is nearly unreadable and many PDFs aren't readable at all. There are issues related to the switch to gcc 4. But the last straw was when printing to my Epson C86 stopped working.

(I try to make a point of mentioning bug numbers when I whine about open source issues. The freetype problem with terminal fonts was already reported as bug 315150, and I opened bug 319068 on the pdf issue though I suspect it's part of the same problem. The gcc4 issues are well known and are just transitional issues. I didn't bother reporting the printer regression; after over a year of having similar bugs for my old printer ignored, finally giving up and buying a new printer specifically so that I could continue to run Debian, it's hard to have much confidence that reporting printing bugs is worthwhile.)

The switchover to Ubuntu was surprisingly painless. The install went fairly smoothly, and in half a day I was up and running with my environment (currently fvwm) customized the way I wanted it. The only problems I've had with hoary are poor rendering of fixed-width fonts (not as poor as sid with the freetype bug, but a lot worse than debian used to be) and inability to play mp3 (I suspect I'll hit problems with other formats such as wmv as well, but I haven't tried yet). The font problem is quite annoying and no change I make to /etc/fonts/local.conf seems to make any difference. The mp3 problem probably requires downloading and hand-installing something -- I hear rumours that there's nothing apt-gettable which will make non-free formats work, though that seems odd for a distro aimed at desktop users.

Update 7/31: Turns out there are hoary packages for mp3 handling after all. Search for "mad" rather than "mp3", e.g. xmms-mad adds mp3 support to xmms.

But first I had to set up a development environment. Ubuntu's install is very minimal, since it uses only a single CD. It doesn't even install gcc by default. So I enabled all the ubuntu sources (restricted, universe, multiverse) and I've been gradually adding packages to get back everything I had on sid.

GIMP (2.3, from CVS) seemed like a good build test. Assembling the dependencies was straightforward but time consuming. Since people new to building GIMP are often confused about what they'll need, I kept track of the additional packages I needed, and posted the full list on my GIMP building page.

[ 12:24 Jul 29, 2005    More gimp | permalink to this entry | ]

Tue, 26 Jul 2005

New Pho

Pho 0.9.5-pre4 seems to be working pretty well and fixes a couple of bugs in pre3, so I posted a tarball. I really need to quit this pre- stuff and just release 0.9.5. Soon, really!

[ 12:51 Jul 26, 2005    More programming | permalink to this entry | ]

Fri, 22 Jul 2005

When gnome loses all your settings

This has bitten me too many times, and I always forget how to recover. This time I'm saving it here for posterity.

The scene: you wanted to check something, perhaps a window manager theme or a font setting or something, and innocently ran some gnome app even though you aren't running a gnome desktop.

Immediately thereafter, you notice that something has changed disastrously in your gtk apps, even apps that were already running and working fine. Maybe it's your keyboard theme, or maybe fonts or colors.

Now you're screwed: your previous configuration files like ~/.gtkrc-2.0 don't matter any more, because gnome has taken over and Knows What's Best For You. How do you fix it?

Don't bother looking for apps that start with gnome-- or gtk-. That would be too obvious. You might think that gnome-control-center would have something related ... but mwa-ha-ha, you'd be wrong!

The solution, it turns out, is gconf-editor, an app obviously modeled after regedit from everyone's favorite user interface designer, Microsoft.

In the case of key theme, you'll find it in desktop->gnome->interface->gtk_key_theme.

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[ 17:39 Jul 22, 2005    More linux | permalink to this entry | ]

Sun, 17 Jul 2005

Seal Nookie

Dave and I spent the morning swapping processors. He's letting me use his old P3 Tualatin to replace the Sempron based system I bought.

The Sempron was what I came up with after I had no luck finding a working motherboard to replace the one that died on my beloved old (quiet and cool) Tualatin machine. The machine always ran too hot. At least, everyone seemed shocked when I mentioned that it typically ran at 59-62°C with the case open and an extra fan blowing onto the chip, and more like 75°C with the case closed (so I've been running it with the case permanently open, which means it's a lot noiser).

That's the second time I've gotten burned by AMD. They make fast chips, but I don't care about speed: I care about cool and quiet operation for the machine I run day in and day out. Intel's no better, as long as a P4 is all you can buy for a desktop machine. The Via C3 line seems to be the only option until Intel finishes their promised switch to desktop processors based off the Centrino line. (I hope when those finally arrive, they're available in a version without DRM.)

After the machine swap was finished, the day had heated up, we headed over the hill to my favorite beach, Bean Hollow, to check out the tidepools and tafoni and harbor seals.

The tidepools had a decent selection of crabs up to about 3 inches as well as goggles of small hermit crabs (mostly in shells of some sort of purple snail).

Apparently it's harbor seal mating season. At least, we guessed that's what they were doing, though they might have just been playing in groups of two, with much flipper-splashing and nuzzling, and crowds of other seals gathered around to watch. There was also a lot of loud, rude sounding snorting from solo seals swimming nearby.

The seals' coats are very colorful, much more so than in spring when they're raising pups. The rocks were covered with seals sporting black-spotted white, white-spotted black, yellow, orange, and red. Quite a change from their spring colors of dark silver to black. One web reference I found said they molt after the pups are weaned, so perhaps these colors represent their fresh coats, which gradually turn duller as they age.

The bright colors are much more photogenic, too. They stand out from the rocks, especially the white youngster who obligingly ran through a gamut of cute poses for me, relaxing, looking alert, scratching, yawning, rolling over, and finally some seal yoga: I didn't know such seemingly ungainly animals could scratch their heads with their back flippers!

[ 00:15 Jul 17, 2005    More nature | permalink to this entry | ]

Sun, 10 Jul 2005

Dark Side of the Moon; M51 Supernova

Yesterday was the annual Fremont Peak Star-b-q. This year the weather managed to be fairly perfect for observing afterward: the fog came in for a while, making for fairly dark skies, and it wasn't too cold though it was a bit breezy. It was even reasonably steady.

I had my homebuilt 8" dob, while Dave brought his homebuilt 12.5". Incredibly, we were all alone in the southwest lot: the most Star-b-q was fairly lightly attended, and most of the handful who stayed to observe afterward set up at Coulter row.

The interesting sight of the evening was the supernova in M51 (the Whirlpool galaxy). It was fairly easy in the 12.5" once we knew where to look (Mike Koop came over to visit after looking at it in the 30"), and once we found it there all three of us could see it in the 8" as well.

We had excellent views of Jupiter in the 8", with detail in the red spot, the thin equatorial band easily visible, and long splits in both the northern and southern equatorial bands. I didn't make any sketches since a family wandered by about then so I let them look instead.

We also had lovely low-power views of Venus and crescent Mercury, and we spent some time traversing detail on the dark side of the slim crescent moon due to the excellent earthshine. All the major maria were visible, and of course Aristarchus, but we could also see Plato, Sinus Iridum, Kepler, Copernicus and its ray system, Tycho (only in the 12" -- the 8" was having glare problems that close to the lit part of the moon) and one long ray from Tycho that extended across Mare Nubium and out to near Copernicus. Pretty good for observing the "dark" side!

Neither of us was able to find Comet Tempel-1 (the Deep Impact comet), even with the 12.5". But after moonset I picked up the Veil and North American in the 8" unfiltered (having left my filters at home), and we got some outstanding views of the nebulae in Sagittarius, particularly the Trifid, which was showing more dust-lane detail without a filter than I've ever seen even filtered.

It was a good night for carnivores, too. We saw one little grey fox cub trotting up the road to the observatory during dinner, and there was another by the side of the road on the way home. Then, farther down the road, I had to stop for three baby raccoons playing in the street. (Very cute!) They eventually got the idea that maybe they should get off the road and watch from the shoulder. The parents were nowhere to be seen: probably much more car-wise than their children (I don't often see raccoon roadkill). I hope the kids got a scolding afterward about finding safer places to play.

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[ 23:31 Jul 10, 2005    More science/astro | permalink to this entry | ]