Messages in this thread | | | Date | Wed, 29 Oct 2003 21:01:41 +0100 | From | Pavel Machek <> | Subject | Re: Blockbusting news, results get worse |
| |
Hi!
> > >> or put it under heavy write workload and remove > > >> power. > > >> > > > Can you tell us more about what really happens to disk drives when the > > > power is cut while a block is being written? We engage in a lot of > > > uninformed speculation, and it would be nice if someone who really knows > > > told us.... > > > > > > Do drives have enough capacitance under normal conditions to finish > > > writing the block? Does ECC on the drive detect that the block was bad > > > and so we don't need to detect it in the FS? > > > > > > Does it really matter to speculate about this? > > > > If you don't FLUSH CACHE, you have no guarantees your data is on the > > platter. > > I think that the idea that is floating around is to deliberately ruin > the formatting on part of the drive in order to simulate a bad block. > > Operation of disk drives immediately after a power failiure has been > discussed before, by the way: > > http://marc.theaimsgroup.com/?l=linux-kernel&m=100665153518652&w=2
Well, that looks like pure speculation.
BTW I *do* believe that powerfail can make the sector bad. Imagine you bump into bad sector during write, and need to reallocate...
Pavel -- When do you have a heart between your knees? [Johanka's followup: and *two* hearts?] - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |