Hi all,
I’m writing a sector based disk encryption filter.
If a bad sector is detected (=read request of the sector fails) during the
initial encryption of a volume I currently skip the volume leaving it only
partly encrypted. This seems to be not acceptable and our customers request
to fully encrypt such a volume.
- Can I rely on ioStatusBlock.Information returning me the size of read
bytes in front of the bad sector ?
- Is there an intelligent way / algorithm to do this without risking
further damage to the drive ?
Regards
Else
2008/1/9, Else Kluger :
>
> Hi all,
>
> I’m writing a sector based disk encryption filter.
> If a bad sector is detected (=read request of the sector fails) during the
> initial encryption of a volume I currently skip the volume leaving it only
> partly encrypted. This seems to be not acceptable and our customers
> request
> to fully encrypt such a volume.
> - Can I rely on ioStatusBlock.Information returning me the size of read
> bytes in front of the bad sector ?
The data and size should be considered both unreliable if you recevied the
sector fails, and I think the best practice is let them be and report the
read status to upper layer.
- Is there an intelligent way / algorithm to do this without risking
> further damage to the drive ?
>
> Regards
> Else
>
>
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> This seems to be not acceptable and our customers request to fully encrypt such a volume.
This is one of the reasons why so-called “evidence eliminators” are objectively unable to give you 100% guarantee that their software safely deletes all the target data (I already don’t mention the fact that you may have multiple copies of a given file’s data on your drive due to defragmentation that their software is totally unaware of). However, computer-ignorant users normally tend to believe their marketing claims about 100% guaranteed data destruction…
Concerning your question, I am afraid you are out of luck - although you cannot read a bad sector on a PC, specially-tuned hardware will be able to recover it without a problem. Therefore, the best thing you can do is to provide “best-effort service”, without 100% guarantee of success…
Anton Bassov