Taking time to check your sums

I’ve got an old laptop that is currently running Windows XP (that was installed on it when it was given to me a few months ago) and at long last I’m getting round to carrying out my intention (which I’ve had ever since I received it and managed to get it to actually work) of putting Linux on there instead.

Since it is a fairly old laptop (a Sony Vaio from either the late nineties or the early naughties, as far as I can tell) and consequently somewhat lacking in system resources by today’s standards, it is likely to work best with a relatively lightweight Linux distribution.  I’ve decided to try out #! (aka. Crunchbang), a variant of Debian built around the Openbox window manager.  This is supposed to be fairly light in its demands on resources so should work ok with limited memory, processor speed and disk space.  If even this proves too much for the old machine, I’ll have to try one of the truly lightweight distros, such as DSL, instead.

I downloaded the ISO file for the latest version of #! last night, via bittorrent as this seems to be the way forward for large downloads.

Fortunately, I’ve adopted the habit of checking the MD5 checksum of any large download I make (I don’t always bother for smaller ones).  The Wikipedia page I just linked to will give you plenty more detail if you want it but, essentially, MD5 is a cryptographic hash function that provides a 32 digit hexadecimal integer (or checksum) corresponding to any input datastream (such as a computer file), in such a way that any change in the data will result in a completely different checksum.  By providing the MD5 checksum of the file as it is supposed to exist, the person sending you the file (or from whose website you download it) enables you to check that the file you have received is the same as the original.  Although MD5 is no longer cryptographically secure (i.e. it is vulnerable to deliberate attack) it still provides a pretty reliable way of checking whether your data has become corrupted in transit.

The reason I mention all this is that, on checking my shiny new Linux ISO file’s MD5 checksum against the one listed on the #! website for the same file, I discovered that it was different.  That meant that my download hadn’t been entirely successful and I was able to discover this fact before wasting time writing the file to a CD (since my laptop is too old to support booting from USB drives) and trying to run it (#! is, I believe, a Live CD distribution that can be installed to the hard drive later if you so choose – as is common with many contemporary flavours of Linux).

At this point, I expected to have to download the whole file (nearly 1GB worth) again and hope for better luck next time.  However, I discovered that bittorrent (using the Transmission client on Linux) had a function to validate my local copy of the file and, when it found a discrepancy, it was able to figure out which bits of the data were missing or corrupted and download them (again?) to create a working file.  On the second attempt, my MD5 checksum matched the expected one, so I am confident that the ISO I now have is a full working copy of the one from the #! website (which presumably should work ok).  Of course, bittorrent’s validate feature probably obviates the need to run a separate check on the MD5 checksum but it’s still nice to be able to get independent confirmation that the file is sound (and it would also still be useful for checking downloads that I haven’t got using bittorrent).

The next stage is to burn the ISO file onto a CD and then have a go at booting my laptop with it.  That’s probably going to be my main task for later this evening.

 

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7 Comments

  1. Don’t forget to check out lubuntu too 🙂 lxde on openbox on ubuntu 🙂

    Reply
  2. As it happens, Lubuntu was the second on my shortlist of relatively lightweight distros to check out. I suspect that if #! proves too much for my geriatric laptop, Lubuntu will too and I’ll have to resort to one of the truly small distros (e.g. TinyCore).

    I’m currently using LXDE on Linux Mint Maya as my main platform on my desktop PC at home. I can’t remember what window manager it uses, but I’ve decided that I like LXDE more than XFCE (mainly due to the better menu handling), MATE, KDE and all the other options I’ve tried.

    Reply
  3. ro2nie

     /  2013/02/06

    I’d install ArchLinux with LXDE on it. It’s a rolling release, and you have to set it up from the beginning which means you have almost no bloatware… It’s just sooo fast.

    Reply
    • I did try out ArchLinux a few years back on my desktop PC. I thought it was a great distro (and pacman is the only package manager I’ve found that seriously gives apt a run for its money) but in the end I switched back to Mint as it seemed easier to maintain. I’ve got the #! CD prepared now so I’ll go ahead and install that on the laptop, but if it turns out to be too much of a resource hog I may try Arch again.

      Reply
  4. The installation seems to have gone well, despite the fact (which I’d overlooked) that the laptop is so old it doesn’t even have an ethernet adapter! I may be able to get it working wirelessly, although my wireless USB dongle didn’t seem to like the last flavour of Linux I tried it on. Even without a network connection, the default software that came on the #! cd seems to contain everything I really need on the laptop (which is not much more than a copy of vim).

    I was hoping to play with it more this evening, but I spent most of the night trying to track down a configuration problem on my (also quite newly installed) Linux Mint Maya setup (with LXDE/Openbox) on my desktop PC. It was refusing to remember my settings for the desktop wallpaper. After an evening spent delving into various log and config files (and doing a fair bit of googling), it occurred to me to check the file permissions in my .config directory and I discovered that a couple of the subdirectories (including one of the important LXDE ones) were owned by root and, presumably, the settings I was trying to update were quietly failing to get saved. I changed the ownership to my own non-root user account and the system is now working perfectly (at least in this respect). It’s frustrating when things fail without giving adequate error messages!

    Reply
    • How are you doing now with Crunchbang, back to ubuntu soon or just happy – I’m tempted to try crunchbang

      Reply
      • It’s limited by the fact I don’t have an internet connection on the laptop so I’m stuck with the default software. I’ll be using it to take minutes at a meeting tonight, which will be its first real test.

        So far I’m liking the look of Crunchbang and I think it has quite a bit of potential. I’ve also installed a copy in a virtual machine on my desktop PC, but I haven’t really had time to play with it yet.

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