Re: Can I compress a partition and keep all the erased data?

Previously Mark M <nomail@xxxxxxxxxxxx> wrote:
QUESTION

Is there a way to save a 160GB NTFS partition in a smaller space and
at the same time to retain ALL the data? That retained data would
include clusters of *erased* data and *erased* system files.

I believe that creating a typical image file of the 160Gb partition
would not include those erased data areas. But is there some other
way to do what I want?

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OBJECTIVE

My objective is to be able go back to this partition and to undelete
data as and when I might need to.

The 160GB partition contains XP Home and is on a PC which is only a
few months old. This means something like 100GB to 140GB of the
160GB is completely virgin space. It seems a pity not to reclaim
this 100GB+ space for use - but only if it's still possible to KEEP
the clusters which contain data but which are not "marked" to say
their data is normally available. (If you see what I mean!)


I think the problem is to determine which space contains data.
It might be infeasible in general. The only option I see is to do
a compressed image-backup (all sectors), where the empty sectors
are compressed very well (since they contain zeros). For that
you will need a target filesystem with enough space to store
the entire partition and a file-size limit also high enough.

Personally I don't know whether there are suotable sector imagers
under Windows. Under Linux you would do something like
cat /dev/sda1 | bzip2 -1 > image.bz2 and a verify afterwards,
e.g. by doing md5 sums of original and image. This might take
several days though.

Arno
.