[dm-crypt] yet another header reconstruction question

Robert Nichols rnicholsNOSPAM at comcast.net
Thu Feb 18 13:53:04 CET 2016

On 02/18/2016 02:51 AM, Florian Dotzer wrote:
> I tried dd on files to replace the first 512 bytes of a file , but
> the target file was completely replaced with this command :
> dd if=512_bytes_with_fixed_header of=file_with_first_64_MB_of_md0 bs=512 count=1

When the target is a file, you need to include "conv=notrunc" so
that the file  will not be truncated to zero length when it is
opened.  That is not an issue when the target is a block device,
but there is no harm in using "conv=notrunc" there, too.

Bob Nichols     "NOSPAM" is really part of my email address.
                 Do NOT delete it.

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