Messages in this thread | | | Date | Tue, 28 Oct 2003 02:21:43 +0100 | From | Pavel Machek <> | Subject | Re: Blockbusting news, results get worse |
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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.
Well, even without FLUSH CACHE, you can expect that sector being writen during powerfail either contains old data *or* new data.
If sector can become unreadable after powerfail, I guess journaling people would like to know, and if powerfail may mean adjacent (or even unrelated?) sectors to be damaged, everyone needs to know... 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/
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