What does CRC error mean?

22 Feb 2006 12:24 PM

Lars Netzel

Hi

I get CRC-errors when I do System.IO.File.Copy from a dvd-r disc to a d:
drive. It works on many computers but not this one laptop.

best regards
/Lars Netzel

22 Feb 2006 12:37 PM

Andrew Morton

Lars Netzel wrote:

> I get CRC-errors when I do System.IO.File.Copy from a dvd-r disc to a
> d: drive. It works on many computers but not this one laptop.

Can you copy the files manually?
Does it work with a different DVD?
Does it work after you use a lens cleaner in the drive?

Andrew

22 Feb 2006 12:56 PM

Patrice

This is something like a Cyclic Redondancy Check i.e. a calculation on
written bytes (and the result itself is written). At read time, the
calculation is performed again and if the result is not the same, this is
because the bytes you read are not those who were written.

So basically it would mean that for some reason, you can't read correctly
the file back (damaged support or whatever, as it doesn't work here with a
particular machine, the drive might be a bit more sensible to external
conditions).

--
Patrice

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"Lars Netzel" <uih***@adf.se> a écrit dans le message de
news:%234D2mr6NGHA.720@TK2MSFTNGP14.phx.gbl...
> Hi
>
> I get CRC-errors when I do System.IO.File.Copy from a dvd-r disc to a d:
> drive. It works on many computers but not this one laptop.
>
> best regards
> /Lars Netzel
>
>

22 Feb 2006 3:19 PM

Lars Netzel

So.. this error happens AFTER the file is actually copied? and the error can
be either...somethinr wrong with the written file... or.. that the reading
of the original fails when doing this check?

/Lars

Show quoteHide quote

"Patrice" <a@bc.c> wrote in message
news:urPFh96NGHA.532@TK2MSFTNGP15.phx.gbl...
> This is something like a Cyclic Redondancy Check i.e. a calculation on
> written bytes (and the result itself is written). At read time, the
> calculation is performed again and if the result is not the same, this is
> because the bytes you read are not those who were written.
>
> So basically it would mean that for some reason, you can't read correctly
> the file back (damaged support or whatever, as it doesn't work here with a
> particular machine, the drive might be a bit more sensible to external
> conditions).
>
> --
> Patrice
>
> "Lars Netzel" <uih***@adf.se> a écrit dans le message de
> news:%234D2mr6NGHA.720@TK2MSFTNGP14.phx.gbl...
>> Hi
>>
>> I get CRC-errors when I do System.IO.File.Copy from a dvd-r disc to a d:
>> drive. It works on many computers but not this one laptop.
>>
>> best regards
>> /Lars Netzel
>>
>>
>
>

22 Feb 2006 11:07 PM

Herfried K. Wagner [MVP]

"Lars Netzel" <uih***@adf.se> schrieb:
> So.. this error happens AFTER the file is actually copied? and the error
> can be either...somethinr wrong with the written file... or.. that the
> reading of the original fails when doing this check?

From my experience I'd say it's more likely that reading the CD failed.

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://classicvb.org/petition/>

24 Feb 2006 2:41 PM

Lars Netzel

OK, that actually makes sence since we got ahold of a bundle of really
crappy DVDs this time.

Thank you!

/Lars

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"Herfried K. Wagner [MVP]" <hirf-spam-me-here@gmx.at> wrote in message
news:uRdyKTAOGHA.3936@TK2MSFTNGP12.phx.gbl...
> "Lars Netzel" <uih***@adf.se> schrieb:
>> So.. this error happens AFTER the file is actually copied? and the error
>> can be either...somethinr wrong with the written file... or.. that the
>> reading of the original fails when doing this check?
>
> From my experience I'd say it's more likely that reading the CD failed.
>
> --
> M S Herfried K. Wagner
> M V P <URL:http://dotnet.mvps.org/>
> V B <URL:http://classicvb.org/petition/>