tar error unrecoverable?

[Colin Law]

On 25 January 2014 20:02, Curt Tresenriter <ctres at grics.net> wrote:
> On Sat, 25 Jan 2014 19:25:01 +0000
> Colin Law <clanlaw at gmail.com> wrote:
>
>> >
>> > Earlier I tried using dd with the noerror option to copy back to
>> > the original disc. syslog shows:
>>
>> Why are you using noerror?  If dd shows read errors then there is no
>> point carrying on.  Immediately backup any important data on the disc
>> and chuck it.
>>
>> Colin
>>
>
> My understanding was that the option would allow me to get whatever
> files are not corrupted out of the archive.
>
> At this point all I can do is backup a supposedly corrupted archive.
> That wouldn't be much use.

All dd does is to make a copy of the file.  If the file cannot be read
correctly from the disc then with noerror it will just ignore the
error (I assume) and carry on copying.  The result is that you will
most likely end up with a file with a bit missing or wrong.  It may be
possible to recover data from the file, but don't bother unless you
really need to.  Have you lost the original files that were packed
into the file?

Colin