Critical Exponent

If you’re reading my site, you’re most likely using an RSS aggregator. If you’re not, get thee to Google Reader, stat.

Google Reader has a cool feature that lets you share with others items in the feeds that you read (and you can event comment as you share!). It also has a bookmarklet to let you similarly share any page on the web. Within Google Reader, you can easily see you friends’ shared items.

In the event you don’t use Google Reader, you can still access my shared items by subscribing to my automatically-generated Shared Items blog. (The most recently shared items also show up in a gadget in my blog sidebar.)

Why care about my shared items? With shared items, I don’t have to debate whether an interesting site merits a whole entry in my blog or a mass mailing to all of my Internet friends/acquaintances/stale contacts. I can point you to articles that, for some reason or another, I found interesting: maybe I agree with them, maybe I don’t; maybe they opened my eyes, maybe they left me incredulous. At any rate, placing these items in a separate repository allows my own blog to focus on original content about my life and my thoughts—much in keeping with the Slow Blogging article I recently shared.

It cleans things up for me as a blogger, and for you as my audience. Check it out!

Somewhere between a vacation and a staycation lies the webcation. On a webcation, one is not completely disconnected from daily life as in vacations of yore; neither is one staying near home, as in a staycation. A webcation is a web-enabled vacation where one checks personal e-mail and the news thanks to the ever-present Wi-Fi hotspots and cell phone data networks. Webcations often take the form of road or bike trips made possible by Web 2.0 features: researching tourist information on the go from one’s cell phone, looking up traffic and maps on Google, downloading apps and blogging from the car….

Next stop: Crater Lake, OR

A week or two ago, I finally upgraded WordPress from 1.5.x to 2.6.2. After the upgrade, I had problems with the layout of the initial page, and problems logging in. Removing the inScript plugin directory and disabling wpPaginate (and updating the Giraffe theme) seemed to fix things. In the meantime, I got many spam comments.

The spam should have been cleared now, and the blog working as normal. Let me know if you encounter any problems….

BTW, I recommend the WordPress Automatic Update plugin. It does make life simpler.

I am a Linux guy. I have a computer that works well. I tweak it and customize it easily. I look under the hood and change things. I can understand how it works. If I need more functionality, I get new software for free, or write my own. Hell, I can even give it back to the community. Like the beater car that greasy-jeaned high-school student is always working on, my computing solution is always a work in progress.

But now I’ve been given an in with the cool kids. Two weeks ago, Knox gave me an iPhone. It is sleek and elegant; the UI is a marvel (go Apple!). Now I, too, can carry this latest status symbol and oh-so-nonchalantly check the Internet on the bus. Now I, too, can pass for the sexy hipster in the Mac commercials.

I feel out of my element.

I don’t like ostentation and, frankly, I’m often not an early adopter: I just don’t have time to mess around with everything so that it works to my satisfaction. My Linux setup is enough; everything else, I’ll use once other people figure out how to make it work.

The phone itself will be useful, of course. You can use it as a phone or a music player, you can track your location in real time and get directions, check the weather or the stocks, email chat take pictures write notes—many things you could do on a real computer though not quite as well but that is alright because you’re on the go and that’s the price you pay for portability, right?

Sure… but what if you’re not productive or hip enough because your phone doesn’t do x, y, or z? Like the rich kids at school, you just throw Daddy’s money at the problem. You can buy and download “Apps” for iPhone right from the device, most for well under $10 (and, in fairness, many of them are free). That in itself is just so weird to me, that the basic software you need to be productive would be proprietary.

Peeking under the hood? Forget about it. You can’t mount the iPhone under Linux; you need to be running iTunes or some other Apple software in order for your computer to recognize the device and access the filesystem. In fact, that is the only way to change the iTunes account the iPhone uses to buy apps. It is also the only way to sync your music or contacts. Hello, Apple? I feel like a second-rate member of your clique.

Making your own software? Just let the mechanics handle that: while the SDK is available for free, developers must pony up $99 to join the Developer Program where they can actually access documentation and be permitted to upload applications to a real iPhone, and then apply to be permitted to sell the apps in the country club App Store. Sure, $99 may not be a lot to someone with the means to get an iPhone in the first place, but it’s an additional disincentive to make the device “yours”, as is the mere existence of an approval process (to say nothing of the backlog) that prevents you from sharing your apps with others as you see fit. For goodness sake, tinkering and sharing were crucial in reaching our technological state!

There is a future for smart phones like the iPhone, no question about it. I’ll spend some time making this my own (do I need to jailbreak it? ugh), and I am excited that this is moving me even more into the Cloud. (I’ve been resisting the Cloud because it wasn’t quite ready for my needs, but it’s getting there.) I can’t wait for the Android phones, though, which will be open source. When they’re ripe, my Mac hubby can get the iPhone and I’ll go back among the nerds where I belong.

Knox got an Airport Express for his Mac. For now, we’ll use it as our music streaming solution, though my eventual goal is to get something like a Squeezebox or Sonos.

Setting up the AEX to work with the Mac was mostly simple, with one caveat: to get onto our existing wireless network, we had to provide the hex version of our 64-bit ASCII WEP key as the 40-bit WEP key the Mac dialog was asking for.

For Linux, it’s slightly more involved. I found out about raop_play, a simplistic music client that, most importantly, includes a driver such that ALSA applications can stream music to a virtual audio card which actually gets streamed to the AEX. Pretty nifty.

I followed Nils Winkler’s instructions for setting up raop_play. Here’s the additional stuff I had to do to get this to work:

• Before compiling, install the following packages libsamplerate-devel fltk fltk-devel libid3tag-devel fltk-fluid

• Delete the line #include <linux/config.h> in drivers/alsa_raoppcm.c

• Patch the kernel module source

• Create Nils’s suggested scripts: load_airport_express_driver, start_airport_express, and stop_airport_express. Modify start_airport_express to have the IP address of the AEX.

At this point, the basic infrastructure was working:

• Run start_airport_express

• Verify the sound “card” is installed: cat /proc/asound/cards

• Play some music: sudo mplayer -ao alsa:device=hw=1.0 some_song.mp3

Unfortunately, I couldn’t run as non-root. My devices on /dev/snd look like this:

 drwxr-xr-x   2 root root        180 2008-04-06 07:44 .
 drwxr-xr-x  14 root root       5200 2008-04-06 07:44 ..
 crw-rw----+  1 root root     116, 6 2008-04-06 07:42 controlC0
 crw-rw----   1 root root     116, 8 2008-04-06 07:44 controlC1
 crw-rw----+  1 root root     116, 5 2008-04-06 07:42 pcmC0D0c
 crw-rw----+  1 root root     116, 4 2008-04-06 07:42 pcmC0D0p
 crw-rw----   1 root root     116, 7 2008-04-06 07:44 pcmC1D0p
 crw-rw----+  1 root root     116, 3 2008-04-06 07:42 seq
 crw-rw----+  1 root root     116, 2 2008-04-06 07:42 timer

The C1 entries are used raop_play, but you’ll notice they don’t have a + in the permissions column. Why is that? What does the + mean? Tell me if you know!

On a hunch, though, I chowned controlC1 and pcmC1d0p to my user group—and I could play as non-root.

Well, mostly. I can stream music from applications that let me select the ALSA device, such as mplayer and xmss. Unfortunately, I don’t see how to configure rhythmbox to use raop_player. (Tell me if you know!)

Knox upgraded to Leopard, and the simple printer sharing (Linux to mac) that had been so easy to set up before stopped working. After implementing the tips here and here, I discovered that the shared printer can be found under the “Default” tab of “Print & Fax”, not under the “IP” tab. Before the upgrade, the shared printer just showed up immediately.

A friend gave us a new Epson Stylus R280 printer (he’s been getting several free ones with his computer and related purchases). This is good; we’ve been needing an everyday-type printer.

I started looking for drivers. The Epson site does not support Linux, but it did point me to the Avasys site, which has a driver. Unfortunately, the source RPM wouldn’t compile, but the downloaded tarball seemed to be working fine. It asked me for the name and location of the device, at which point, crossing my fingers, I proceeded to unpack the printer and hook it up….

And CUPS just recognized it instantly! I didn’t even have to finish the manual setup of the driver I had downloaded. The test page came out fine!

Is this what life is like for Mac users?

During this vacation, I upgraded to Fedora 8. Here are some gotchas and caveats I encountered:

• Make sure you check the install image checksum. If first downloaded the installation DVD using BitTorrent. It took over a day and the file wound up corrupt. I had to download the image directly, which took only a couple of hours and worked fine. I’ve only tried to use BitTorrent for these Fedora updates, so I’m not sure whether it is inherently slow or I have it badly misconfigured; I do know it’s supposed to checksum the files to prevent corruption.

• The Anaconda installer would not run off the DVD on the laptop. I read that the fix is to append the following to the kernel boot line:

  floppy.allowed_drive_mask=0 clocksource=acpi_pm

• When attempting to initiate the install on my desktop (which I tackled before the laptop, so as to have one computer operational during the process), which has migrated over the years from customized RedHat through various incarnations of Fedora, I got an error saying that filesystems “should be specified by label, not by device name”. The fix is to rename, in fstab, /dev/hd... to /dev/sd...

• When Anaconda was trying to resolve package dependencies, it would hang at 26%. Switching to tty3, I saw the message “No package matched to remove”. It turns out this is a bug in yum. The fix is to append the following to the kernel boot line:

  updates=http://katzj.fedorapeople.org/updates-f8-yumloop.img

• I installed the Suspend2 (now TuxOnIce) kernel. I could not get it from mhensler’s repository, so I installed it from the livna repository instead. Hibernation works fine, but suspend-to-RAM is no longer working (I can’t resume, and often it seems as though the kernel is fine but the display does not turn on on resume). I am playing around with the sleep quirks to see wheter there’s some incantation that will resolve the problem, but no luck thus far. It’s a shame, too; it’s really useful to suspend at the touch of a button as I could with F7.

• The official recommendation from Fedora is not to install the proprietary nVidia video driver, as it does not play well with the rest of the system in case you need to uninstall it later. Packaged drivers are available from livna, but they are compiled against the vanilla kernel and not the TuxOnIce kernel. I tried briefly to compile the proprietary nVidia driver against the TuxOnIce kernel, but the installer had problems finding the kernel sources. I suspect this is a book-keeping problem in yum or the repos (since the sources and headers are marked as installed), but I haven’t tracked this down yet.

• At the application level, as always, I refer as needed to mjmwired for the installation of useful packages.

While the suspend-to-RAM issue is big demerit, the rest of the distribution is looking pretty good in use. I got updates of packages I use all the time, and a few things are more polished (such as the mail notification on the panel and the new gdm greeter).

Not an early adopter, I. Not for technologies I’m not helping develop….

I finally upgraded to Fedora Core 7. It went smoothly, with just two hiccups, one which Fedora could ease, and the other which was entirely my fault but serves as a good warning of how things could go wrong.

When updating the laptop, Anaconda complained about there not being enough space to proceed with the installation. I had to resize my root partition. Partition resizing is relatively easy in general if you’re using Logical Volume Management (LVM), as I am, but has an extra wrinkle when you’re trying to resize the root partition itself. Here are the steps that I took, gleaned from various sourced but mostly from the LVM HOWTO:

• Boot from the rescue disk, mount filesystems when prompted

• Unmount the partition you’ll be shrinking to make room for the partition you’ll be extending. My shrinking partition was /dev/VolGroup00/LogVol06, mounted on /mnt/sysimage/scratch

  umount /mnt/sysimage/scratch
  

• Check the shrking partition’s filesystem

  e2fsck -f /dev/VolGroup00/LogVol06
  

• Resize the shrinking partition’s filesystem. The second argument below is the new size of the partition expressed as the number of 4K blocks

  resize2fs /dev/VolGroup00/LogVol06 965120
  

• Reduce the shrinking partition, extend the growing partition. In my case, the growing partition was /dev/VolGroup00/LogVol00

  cd /usr/sbin
  lvm lvreduce -L-350M /dev/VolGroup00/LogVol06
  lvm lvextend -L+350M /dev/VolGroup00/LogVol00
  

• Reboot from rescue disk, do not mount filesystems when prompted

• Expand the growing partition’s filesystem

  cd /usr/sbin
  lvm vgchange -a y
  e2fsck -f /dev/VolGroup00/LogVol00
  resize2fs  /dev/VolGroup00/LogVol00
  

After doing all this, I could successfully upgrade my system.

The second hiccup occurred on my desktop. After upgrading and a day or so of subsequent use, I suddenly found that post-boot, the login screen (gdm) would not appear; in its place, X showed only a message box that said Greeter application appears to be crashing. Attempting to use a different one. VNC sessions would not boot up properly, logging instead (in ~/.vnc) a different message: GConf Error: Failed to contact configuration server; ...

After much web research, I found two possible culprits. One was the accessibility option in gdm, so I turned that off: I sshd in remotely, ran gdmsetup and turned off accessibility. That made the greeter show up, and I could log in….but my session immediately terminated with a different dialog box showing a log message that I was out of disk space. VNC sessions still would not initiate properly.

The other possible culprit was my root partition being full. Unlike my laptop, my desktop does not use LVM, as I’ve been upgrading through several generations of Linux for, egads, eight years now. df showed my root partition being full at 100%, although, interestingly, the ratio of the df-reported Used and Available space was clearly less than 100%. Apparently, the system restricts about 10% of the disk from non-root use (otherwise Really Bad Unrecoverable Things Happen), and df takes that into account when reporting the Use% column.

Anyway, I deleted or moved/symlinked all the files or directories that I thought were safe, but to no avail. I discovered on the Internet that a standard utility, parted, will resize partitions—but you can’t change the starting location of an ext2 or ext3 partition, and in my case, the root partition was the last one on the disk. I was really SOL, up a creek without a paddle, on a trip without a toothbrush….you get the idea.

This particular story had a happy ending, though. Looking through / again, I discovered backup directories that shouldn’t have been there. Apparently something had gone wrong with my automatic back-up scripts and they had been written to the wrong location. I deleted those directories, my root partition usage fell by almost half, and my system is functional again.

The morals of this story are:

• never let your root filesystem get too full
• use LVM whenever you can to make partition resizing easier

I just found out via Reclusive Leftist that it is officially Delurking Week. I know my blog does not get many regular visitors yet, but if you read me, won’t you please consider saying “Hi!” in a comment?

Cheerio, and happy reading!