On Sat, 16 Oct 2004 21:29:32 +1000, Russell wrote in message <[EMAIL PROTECTED]>:
> On Fri, 15 Oct 2004 23:33, Arnt Karlsen <[EMAIL PROTECTED]> wrote: > > > On Fri, 15 Oct 2004 03:19, Arnt Karlsen <[EMAIL PROTECTED]> wrote: > > > > > Increasing the number of machines increases the probability of > > > > > one machine failing for any given time period. Also it makes > > > > > it more difficult to debug problems as you can't always be > > > > > certain of which machine was involved. > > > > > > > > ..very true, even for aero engines. The reason the airlines > > > > like 2, 3 or even 4 rather than one jet. > > > > > > You seem to have entirely misunderstood what I wrote. > > > > ..really? Compare with your average automobile accident and > > see who has the more adequate safety philosophy. > > If one machine has a probability of failure of 0.1 over a particular > time period then the probability of at least one machine failing if > there are two servers in the cluster over that same time period is > 1-0.9*0.9 == 0.19. > > > [EMAIL PROTECTED], "2 boxes watching each other" or some such, will give > > that "Ok, I'll have a look some time next week" peace of mind, > > and we don't need symmetric power here, one big and one or > > more small ones will do fine > > Have you ever actually run an ISP? ..no, I'm an aeronautical engineer and likes Zeppeliners. ;-) -- ..med vennlig hilsen = with Kind Regards from Arnt... ;-) ...with a number of polar bear hunters in his ancestry... Scenarios always come in sets of three: best case, worst case, and just in case. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
