Re: Blockbusting news, results get worse

[John Bradford]

Quote from Jeff Garzik <jgarzik@xxxxxxxxx>:
> Hans Reiser wrote:
> > Mudama, Eric wrote:
> > 
> >>
> >> 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

John.
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