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? -- http://www.coker.com.au/selinux/ My NSA Security Enhanced Linux packages http://www.coker.com.au/bonnie++/ Bonnie++ hard drive benchmark http://www.coker.com.au/postal/ Postal SMTP/POP benchmark http://www.coker.com.au/~russell/ My home page -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
