Btrfs: broken by design?

Posted Jun 24, 2010 13:12 UTC (Thu) by NRArnot (subscriber, #3033)
In reply to: Btrfs: broken by design? by johnflux
Parent article: Btrfs: broken by design?

I put a comment against the QOTW. Basically, it's whether one wants provable behaviour in all circumstances, or whether pragmatism rules. There are very many things that "work", even though you can't prove that they always will. Indeed, there are many useful things which one can prove have a small (hopefully thermodynamically small) chance of total failure.

I can't prove that my head won't fall off before I finish typing this. It's thermodynamically possible, but so unlikely that it won't happen even given a googleplex of universes to try it out i

Btrfs: broken by design?

Posted Jun 25, 2010 14:09 UTC (Fri) by tialaramex (subscriber, #21167) [Link]

A really easy example is the "Two generals problem". We know (mathematical proof, and frankly you can work it out with some thought and no training) that you can't achieve the reliable agreement required in this problem. But it appears that many every day things require such agreement. You can't create a TCP connection without it, for example, or buy something with a credit card.

In reality what happens is that we put up with a negligible chance of failure. The failure of this sort are vastly outweighed by more pragmatic problems (imagine if the generals managed their agreement, and then one finds his men have developed dysentery and cannot fight) so we don't worry about it very much.