Andrew's Stuff

LVM + ReiserFS Partition Recovery


Almost a year ago now, I had one of the legs of an LVM mirror fail. Ordinarily, this should not be a problem, however my particular set-up was a little odd. Specifically, I was passing both physical disks through to a kvm/libvirt virtual machine, and then applying LVM there, with both disks as standard mirrors of each other with a handful of ReiserFS partitions on top. While the disks were healthy, this was no problem at all and it worked fine. Unfortunately, when one of the disks started failing, while the host could see that it was clearly broken - it was reporting I/O errors pretty constantly - the guest was just hanging all the time but refused to acknowledge that it was actually dead.

As it was a long time ago now, I don't recall all of the details, but I think that I then removed the disks from the VM and attempted to recover things directly on the host. Unfortunately the host and the guest assigned different UUIDs to the disks, so this was an absolute disaster. After a whole load of fruitless LVM commands I was left with two disks that theoretically contained the same data as each other, one still working flawlessly, but being only one leg of a mirrored pair and LVM was refusing to let me activate any of the logical volumes on it because the other disk was missing. "Yes, of course it's missing! It's a dead disk! Now let me mount this bloody thing so I can copy the data off of it and onto a new (much larger) disk!"

I've had an interesting thought...


Over the past few days, a couple of things have crossed my Twitter feed.

One of them is the army of people who (probably-erroneously) believe that random food additives (e.g. aspartame) are causing all kinds of ill health. There is not a shred of evidence to support most these claims, so as far as the scientific and medical community is concerned, these campaigners are wrong and just spreading FUD.

Global Usage of IE6 and IE7


Here's some fun data. The percentage of people using Internet Explorer 6 in each country in November 2012, according to StatCounter (direct CSV link). All unlisted countries have less than 1% usage (at least, that's my interpretation of them having a value of "0" in this CSV!).

  • China: 7.31%
  • Eritrea: 5.49%
  • Chad: 4.75%
  • Myanmar: 4.63%
  • Swaziland: 2.17%
  • Rwanda: 1.95%
  • Cuba: 1.78%
  • Burkina Faso: 1.41%
  • Zambia: 1.39%
  • Sao Tome and Principe: 1.39%
  • Samoa: 1.37%
  • North Korea: 1.34%
  • Papua New Guinea: 1.31%
  • Niger: 1.3%
  • Iran: 1.29%
  • Saint Helena: 1.27%
  • Lesotho: 1.25%
  • Equatorial Guinea: 1.23%
  • India: 1.17%
  • Tanzania: 1.17%
  • Central African Republic: 1.16%
  • Togo: 1.08%
  • Taiwan: 1.05%
  • Guinea-Bissau: 1.05%

Honda's Hybrid Jazz - Initial Thoughts


I've only been driving my new Jazz Hybrid for 2 days, but that's long enough for me to have formed some initial impressions of it. Here are the photos that I've taken of it, if you haven't already seen them, and here is the new Jazz on Fuelly if you'd like to keep track of the mileage I get from it.

Firstly, the blue dashboard lighting looks amazing. Non-Hybrid Jazzes have orange instead and, IMO, that looks nowhere near as good. The blue ambient footwell lighting and illuminated doorstep garnishes that I paid extra for compliment it nicely.

Unhelpful Kitchen Light Placement


We’ve long been frustrated by the lighting in our kitchen – both by the power that it consumes, and by the sheer unhelpful positioning of the bulbs. They are all Halogen-style spot bulbs and are positioned annoyingly far away from the work surfaces, giving an end result of very little light actually reaching the work surfaces – the areas that you need to be able to see more than any other.

It occurred to me recently that the light fittings are probably so poorly-located that some simple maths could demonstrate the problem, i.e. the difference between the angle from the light fittings to the surface and the angle at which the bulbs output light (being spotlights, the majority of their output is concentrated into a fairly narrow beam). So let’s investigate this theory.