Re: tar -c -G -N <date> query

[Stepan Kasal]

Hello Tom.

On Wed, Jul 16, 2003 at 07:00:47PM +0100, Tom Crane wrote:
> One question: Can I fabricate a snapshotfile? The format appear to be

though I don't have experiences with it myself, I think I heard it's
possible.

> time_t format timestamp
> device_number directory-inode-number directory-spec
> device_number directory-inode-number directory-spec
> device_number directory-inode-number directory-spec
> etc.

> If I were to invent dummy device_numbers (or obtain the device-->numbers
> mapping??), read the directory inode numbers and directory names out of my
> *full.tar.bz2 tarfiles, and write them to a file with the above format,
> would this do? 

I think it should work.  You can try the method on a smaller test tree.

But it's not enough to invent device numbers.  These numbers are unique
for each device listed when you run ``mount''.
(They are probably calculated from major and minor device numbers, as
listed by eg. ``ls -l /dev/hda1''.)

I'd suggest that you run tar with ``-g'' on a small portion of each
tree mounted by ``mount'' to get the mapping.  Then you can fabricate
the file.

(BTW: if the device is a nfs device, the device numbers are not significant
and you can use any dummy number.)

Good luck,
        Stepan Kasal