Phly, boy, phly
the weblog and site of Matthew Weier O'Phinney

Ever wonder what's keeping that device in use so you can't unmount it? It's happened to me a few times. The tool to discover this information? lsof.

Basically, you type something like: lsof /mnt/cdrom and it gives you a ps-style output detailing the PID and process of the processes that are using the cdrom. You can then go and manually stop those programs, or kill them yourself.

I'd read that you could get binary packages for gentoo, thus alleviating the need to compile everything. (Of course, then you lose some of the benefits of compiling everything, but you gain in speed...) Unfortunately, I mistook this with ebuilds, and never quite figured it out.

The key is to throw the -g flag:

    % emerge -g gnumeric # which is like 'emerge --getbinpkg gnumeric'

I also learned how to update packages tonight:

    % emerge sync             # to sync your mirror with the gentoo mirrors
    % emerge --update portage # if necessary
    % emerge --update system  # updates core system files
    % emerge --update world   # updates all packages 

I've had a bunch of problems with my new computer -- it uses ACPI, but if I load the ACPI modules, it won't boot; if I don't load them, I have to go through contortions to get the ethernet working, and it won't power down; and a bunch of other little stuff.

So, a few weeks ago, I thought, what the heck? Why not try Gentoo? I've been reading about it since it first came out, and I remember talking with Duane about it once, and it has a reputation for both being cutting edge and stable. Heck, even Wil Wheaton's endorsing it... it can't be all bad, right?

I had a few misstarts -- bad CDs, not quite getting how the chroot thing worked, problems with DNS (which I still don't understand; and Rob has them as well, so it's not just me). But once I got it installed... well, I'm impressed.

The thing about Gentoo is, it compiles everything from source. It's like Debian, in that it fetches all dependencies and installs those... but it's all source. So it's not exactly fast. But because everything is compiled, and because you setup C flags specific to your machine, what you get is incredibly optimized for your own machine. This 1.6GHz machine simply flies. And the memory usage just stays low.

I'd like to use it for my server... but I can't really take the server down at this point when it's making both my mom and myself money. But what a great system... I only wish I'd used it for the mail server at work.

I just read coverage of a panel of programming luminaries on Salon; the topic of discussion was about the state of programming. In the course of the discussion, the subject of Open Source came up. Several of the luminaries -- which included architects of the Mac OS and Windows, as well as others -- derided the community for basically reinventing the wheel, and wheels that need to be re-thought entirely anyways. One questioned, "Why is hte idealism just about how the code is shared -- what about idealism about the code itself?"

Andy Hertzfeld (who helped develop the original Mac OS) was sitting on the panel, and jumped in. He has been working with Eazel and Chandler in recent years, and thus has an inside view of open source. His initial comment: "It's because they want people to use the stuff!" Basically, they program Windows- or Mac-like interfaces because then people will be willing to try it out. They program office suites because people "need" an office suite to be productive. Such offerings hook them into the OSS movement.

Another participant, Dan Bricklin (of VisiCalc, a pioneering spreadsheet program) shared an anecdote from Bill Gates. Evidently, Gates gave an interview (with Lammers -- look up this person) in which he explained that his work on MS's BASIC compiler was done by looking at how other programmers had accomplished the task. In his own words, "The best way to prepare is to write programs, and to study great programs that other people have written. In my case, I went to the garbage cans at the Computer Science Center and I fished out listings of their operating systems."

So basically, Gates was an early adopter of OSS methodologies... Interesting to see that today he's so protective of MS code. Guess money might do that to you.

Last night, I created my first RAID array from the commandline. It was quite simple, I discovered.

1. Create your partitions using fstab. Remember, primary partitions must be created before extended partitions.
2. Look in /proc/partions and note the new partition IDs.
3. Edit /etc/raidtab and create a new RAID array. If unsure of the syntax, look up the Linux Software RAID HOWTO for more details.
4. Type mkraid /dev/md?, where ? is the id of the RAID device you just entered in /etc/raidtab.
5. Format the new RAID device with your favorite filesystem, assign it a mount point, and start using it!

I was impressed with how easy it was; the choices that the Anaconda installer present for creating a RAID array made it seem like the underlying process must be difficult, when in fact it may have been almost the same complexity if not easier.

Linux.com has had a running series on CLI commands for Newbies. Most of it has been very basic, but there are still a few gems within. For instance, today I was introduced to apropos and whatis. Give a search term to the former, and it will list all programs in which the search term is found in the manpages; give a program name to the latter, and it will tell you which man page addresses it.

I've had occasion to need to grab a specific set of files from a large directory -- most recently, I needed to grab some specific access logs from our Apache logfiles at work.

Enter find.

I needed to get all files newer than a specific date, and with the pattern 'sitename-access_log.timestamp.gz'. I then needed to tar up these files and grab them for processing. So, here's what I did:

• The -newer filename tells find to locate files newer than filename.
• The -regex flag tells find to locate files matching the regular expression. The regex that find uses is a little strange, however, and didn't follow many conventions I know; for one thing, it's assumed that the pattern you write will match against the entire string, and not just a portion of it. What I ended up using was -regex '.*access_log.*gz', and that worked.
• The -printf flag tells find to format the printing. This is useful when using the output of find in another program. For instance, tar likes a list of filenames... so I used printf "%p ", which separated each filename with a space.

I then backticked my full find statement and used it as the final argument to a tar command; voila! instant tar file with the files I need!

I just ran into this not long ago, and wish I'd discovered it years ago. Basically, Ctrl-S suspends a process, while Ctrl-Q resumes it. This is useful when in g/vim or screen and you manage to lock up your application because you accidently hit Ctrl-S when reaching for another key combo.

I wrote up a short tutorial today on the IT wiki about SSH tunneling. What I didn't know is that you can start a tunnel after you've already ssh'd to another machine. Basically, you:

• Press Enter
• Type ~C

and you're at an ssh> prompt. From there, you can issue the tunnel command of your choice: -R7111:localhost:22, for instance.

I was just reading an article about the Dean campaign's IT infrastructure, and there's an interesting quote from their IT manager, Harish Rao:

"I believe in three principles", he said. "First I always make sure I hire people I can trust 100%. Second, I always try to hire people who are smarter than I am. Third, I give them the independence to do as they see fit as long as they communicate about it to their other team members. We've had a lot of growing pains, a lot of issues; but we've been able to deal with them because we have a high level of trust, skill and communication."

I know for myself that when I (1) don't feel trusted, and/or (2) am not given independence to do what I see as necessary to do my job, I don't communicate with my superiors about my actions, and I also get lazy about my job because I don't feel my work is valued.

Fortunately, I feel that in my current work situation, my employers followed the same principles as Rao, and I've felt more productive and appreciated than I've felt in any previous job.