I recently installed Linux Mint 7 on a laptop. But whenever I’d shut it down you’d hear a really loud beep from the internal pc speaker. Very loud and very annoying. Here’s what I did to stop it:

To disable it now, for this session:
sudo modprobe -r pcspkr

Then to disable it permanently:
Add this line to the bottom of /etc/modprobe.d/blacklist.conf
blacklist pcspkr

Problem solved. No more annoyingly loud beep.

concatenate AVI files:

mencoder -oac copy -ovc copy -o output.avi input1.avi input2.avi

capture webcam stream to an AVI file:

mencoder tv:// -tv driver=v4l2:width=800:height=600:device=/dev/video0 -ovc lavc -o capture.avi

cool ImageMagick tricks

There are so many cool tricks you can do with this package that it’s hard to know where to begin to describe all its features. But here are some that I find useful.

resize all JPEG’s in the current directory to a size of 640×480:

mogrify -resize 640x480 *.JPG
CAREFUL! mogrify overwrites the originals

create thumbnails:

mkdir thumbnails
mogrify -path thumbnails -thumbnail 100x100 *

resize by half:

mogrify -resize 50% somepic.jpg

convert from one format to another:

convert somepic.jpg somepic.png

take a screenshot:

import -window root screen.png

or just a single window (select with mouse):

import screen.png

Recently my co-worker, Mark, has become more interested in Linux.  (Windows has a tendency to do that to a person.)  So he asked me which distro I thought he might want to try out.  At first I suggested Ubuntu might be a good choice for him.  It’s got a huge support community, it’s very stable, and it’s one of the more ‘newbie friendly’ distros.  Mark’s dabbled with Linux in the past, so it’s not like he’s a complete n00b when it comes to Linux.  But still, it might not be a great idea to experiment with a more bleeding edge distro like Fedora.  But Mark is also our graphic designer (with a good eye for design, I might add).  And I HATE that dog poop brown default theme Ubuntu uses.  Yes, I know you can change themes and backgrounds. 

So after thinking about it for a few minutes, I suggested he might want to try out Linux Mint.  It’s a distro that’s derived from Ubuntu, so pretty much any support you can get for Ubuntu will also work for Mint.  They actually use the same repositories, if I’m not mistaken.  But Mint is beautiful!  And it’s also pre-loaded with some restricted media codecs and some other things that just make the user experience that much better.

So he took a look at some screen shots from their website and liked the looks of it and decided to download the ISO image.  We burned that to a disc and started the install process.  We booted the live CD session and immediately he noticed that the ‘dead soundcard’ he had in his machine with Windows wasn’t actually dead at all.  Linux automagically detected the soundcard and loaded the proper drivers.  Just another anecdote to dispel the ‘limited hardware support in Linux’ myth.  After he poked around a little and liked the looks of things he decided to do the install.  I suggested that until he’s ready to make the full transition from Windows to Linux, it would be a good idea to dual boot both operating systems.  I also told him about the possibility of using a Windows virtual machine inside Linux itself.  But dual booting is a good way to start.

The hard drive in that machine isn’t very big.  I think it’s about 80 GB or so, but plenty for holding both Windows XP and Linux, as long as you’re not ripping an entire audio collection or DVDs.  So during the install process Mint uses gparted to help you resize your existing partitions.  This is pretty much standard across all major distros.  We told it to free up about 16 GB of space by reducing the size of the partition holding Windows.  Then we told it to use the newly created space for Linux using the suggested formatting scheme.  This normally works pretty flawlessly in my experience.

Not this time.

I’ve forgotten the exact error message we got, but basically it failed to shrink the Windows partition.  But, no harm, no foul.  It didn’t destroy any information.  I told him to reboot into Windows and run chkdisk and allow it to fix any NTFS problems it might find.  I can’t really fault gparted for this.  After all, NTFS is a proprietary file format.  You can’t really expect gparted to fix problems in NTFS.  So sure enough, chkdisk did find some problems with the filesystem and supposedly fixed them.  But before he allowed Windows to boot completely, he shut it down and booted from the Mint install disc to try the install again.  This was a mistake.  I actually didn’t see him do this.  I was working on other things at the time.  So anyway, he tried the install again, resizing the partitions just like before, but again the same result.

So this time I told him to reboot Windows and allow chkdisk to fix the problems and this time to completely load Windows before shutting down.  Also, this time I suggested booting a gparted live CD that I had.  I thought that might give us some more control over the resizing process before doing the actual install.  We basically did the same thing as before, attempting to free up about 16 GB of space.  But gparted reported some errors again, telling us that we should try freeing up a smaller size.  So for the next attempt we told it to free up only about 5 GB.  This worked.  So we did that a couple more times until we finally had about 16 GB free.

Then we booted Windows just to make sure everything was OK with the new, smaller partition for Windows.  Worked fine.  So we booted the Mint install disc and started the install process.  Just like we expected, it saw a new, empty partition of 16 GB where it could install itself.  We used the suggested partitioning scheme and proceeded with the installation.  The installation seemed to go perfectly.  When it was done, we rebooted and saw the GRUB menu listing both Mint and Windows.  We chose Mint and it booted it as it should.  We were met with the GDM login screen for Mint.  He logged in using the user he set up during the installation.  After a few seconds of a blank screen I told him, “Don’t worry.  For this first boot it will take a little longer than it normally will because it’s setting up your home directory with all its default options.” But after about 30 seconds of not seeing his new desktop I started getting a little worried.  After about 2 minutes I said, “OK, something’s wrong.  Hit ctrl-alt-F3 and let’s get a terminal and see what it is.”

After logging into the terminal (no X session, of course), I told him to enter “df -h”.  I was pretty shocked at what I saw.  It showed that his root partition was allocated only 2.3 GB of space, with 0 bytes free.  Well, that explains what the problem is.  There’s no space available for creating his home directory.  But that doesn’t tell me why the suggested partitioning scheme that Mint used didn’t use the entire 16 GB that was free and available.  So I said, “Wow, that’s weird.  Well, I guess let’s go back and do the install again and see what happens next time.” (Wasn’t it Albert Einstein that said that insanity it doing the same thing over and over again and expecting a different result?)  Fortunately, it only takes a matter of minutes.

So we did the installation over again, and again allowed the installer to set up the partitioning scheme.  Same exact result.  For whatever reason, it only allocated 2.3 GB of space for the root partition.  So when we logged in again it again couldn’t set up his home directory because again there were 0 bytes available.  So this time I said, “OK, forget Mint’s suggested partitioning scheme, I’m going to manually tell it how I want it to be set up.” So that’s what we did.  I allocated 1 GB for the swap partition, and another 15 GB for the root partition and proceeded with the installation.  (I normally put /home in its own partition, but since we didn’t have much space I didn’t do that this time.)

This time it worked like a charm.  He now has a shiny new OS to play with.  After installing the nVidia driver and setting up Compiz, he was blown away by the abilities of his old computer.  And dual booting a computer is a really good way of “comparing apples to apples” since it’s the same hardware being run by two different operating systems.  Plus, it only took about 30 seconds to set up his printer.  Compare that to Windows where you’re searching through drawers and closets looking for that Windows driver disc that came with your printer.  If you finally find it, it may or may not install properly, and there’s a really good chance you’re going to have to reboot to get it recognized.  Then, of course, you’re going to need to find the most recent driver from the manufacturer’s website.  And that’s assuming they still support it.  Then another reboot.  All the reasons I left Windows behind years ago.

Getting back to the Mint partitioning problem, I’ve googled around but I can’t seem to find much evidence of this being a problem other people have encountered.  So I still have no idea why it happened.  But it happened twice, exactly the same way both times.  So I don’t know.  Maybe we uncovered some obscure bug that only happens under certain circumstances.  Or maybe I made some stupid mistake along the way somewhere.  I may not be the most skilled Linux geek around, but I think I have a pretty good handle on things.  But I don’t think ‘grandma’ would have been able to diagnose and fix the problem.  That’s a little bit troubling, since I’d love to see Linux become more widely adopted by casual computer users.

Kevin