Matt's Blog

The first computer in the draisey.ca domain, the dell dimension L600cx had an exceedingly boring name --- I called it della. Boring. The new machine has a far better name --- it is Thoron. What a heroic sounding name. It is really a decay product of Thorium with a half-life of 5 seconds and should properly be called Radon 220, but Thoron sounds just right. Neither della nor thoron are reachable from the internet except by mail, though I may eventually add them via ip6. That has been a pet project I have put off for a good 5 years. It is about time I hardened my network and give it a shot.

The fan has been really annoying with sudden surges to full speed for no apparent reason, but strangely it would only perform its worst gyrations when the machine was the least loaded. I have recompiled the kernel with dynticks disabled hoping that will workaround whatever faulty logic is ultimately causing this. It seems to work so far but being the coldest day of the year I could be deluding myself.

I am quite happy with the MoinMoin site I set up last week, but naturally not a sole is using it. I wonder why I bother to do this. It wasn't very hard to do, if a little time-consuming up-front trying to wade through the documentation for the half-dozen or so wiki's I was evaluating. I set up the dirt simple cgi script which is needlessly wasteful of cpu cycles but much easier on brain cycles.

It is suposedly quite easy to run with the twisted webserver (and a reverse proxy through Apache to resolve the virtual doamin). I might give that a go. It will give me an excuse to play with django at the same time.

let A be a m by n matrix considered as a list of columns
construct B, an n by m matrix (considered as a list of rows), by elimination
such that BAB = B, ABA = A and AB an orthogonal projection onto the image of A

in exact artihmetic and pythonesque psuedo-code:

B = array(A)
for k,a in enumerate(A):
    v = B[k] # pivot row
    va = inner(v,a)
    if va: # note that v nonzero if and only if va positive
        v *= 1/va # scale on <a>
        for j,b in enumerate(B):
            if j == k: continue
            b = b - inner(b,a)*v # elimination on <a>

1. A wiki for the Sailor's Nite Out (on Wednesdays)

   I am going to call it snow.sailclub.ca.

   So far the candidates for installation are:

   • DokuWiki
   • MediaWiki
   • PmWiki
   • MoinMoin
   • Nanoki

2. A mailing list manager for South Port

   Mailman is the only candidate so far.

So the new machine is plenty fast, but not yet up to snuff.

I managed to get a working kernel on my fourth compile. The first three would have been ok but for my disabling initrd support and compiling in support for every filesystem except the one I needed to boot (nested kernel options and the outermost one I had left as M). Grub concealed the true problem through trying to pass UUIDs to the kernel for the root device, which it didn't understand. This is first time I have used grub, and I don't see the advantage over lilo.

X is a pain. I am using the VESA driver as the intel driver doesn't work yet for my G45 chipset. Or perhaps it works but requires a compile of the latest git tree of the entire X server. Modular X it aint. I am getting some weird failures on starting X, that appear to be interactions with the X server. You can't push it too quickly.

The processor fan is another oddity. I have good sensor data from the two cores of my microprocessor, and they never get up to body temperature, but the fan will surge up to full speed ever now and again for no apparent reason. I think this may be a kernel bug, but am not too sure.

That was my assumption until now. Will have to revise to Readership = almost nobody.

Well I getting the new computer going. I didn't do a straight migration from the old machine as I had been planning. The new machine (a dell Vostro 220) needs a fairly new kernel and I just didn't feel like debootstrapping from a live CD. That was my original plan, but it was looking to be such a pain, and wouldn't work with the CD's I had burned, and I could get started with a Lenny netinst CD almost right away and let the thing run overnight without supervision.

Of course now I have a load of work getting things straight so a night saved wasn't such a great economy. Copying over the home directory was easy enough but I still haven't got all the dpkg selections from the old machine downloaded yet. My download speeds are lousy. I am installing software piecemeal.

I am helping to give a talk at my sailing club in the new year. It is entitled 'Sailing Resources in the New Millenium' --- I love how cheesy the name is. It is to introduce the grey brigade at our club to all the cool sailing related things on the web. To this end I have set up an account on delicious to share links with my fellow presenters. Trouble is I am the only one doing anything. People just don't seem to like these tools. Sigh.

I have installed the firefox add-on and it seems to work seemlessly enough. I isn't as sophisticated as I imagined it to be. I wonder what the attraction is?

Most web server applications are constrained by their design to mix upstream source together with local configuration and possibly local storage all together in the same directory hierarchy. This clearly creates maintenance problems, which each project deals with in its own fashion. Modern web servers are more than sophisticated enough to merge the web visible hierarchy of urls from several different root directories, so the ideal solution to this problem is not to have it in the first place --- namely, by keeping upstream and local source well separated on disk. But historical baggage and coding conventions lock us into situations which are less than ideal. It's the system administrators job to deal with it anyway.