Re: Tux3 Report: Initial fsck has landed

[Daniel Phillips]

On Sun, Jan 27, 2013 at 10:02 PM, David Lang <david@xxxxxxx> wrote:
> On Sun, 27 Jan 2013, Daniel Phillips wrote:
> The thing that jumps out at me with this is the question of how you will
> avoid the 'filesystem image in a file' disaster that reiserfs had (where
> it's fsck could mix up metadata chunks from the main filesystem with
> metadata chunks from any filesystem images that it happened to stumble
> across when scanning the disk)
>
> many people with dd if=/dev/sda2 of=filesystem.image, and if you are doing
> virtualization, you may be running out of one of these filesystem images.
> With virtualization, it's very likely that you will have many copies of a
> single image that are all identical.
>
> have you thought of how to deal with this problem?
>
> David Lang

Only superficially. Deep thoughts are in order. First, there needs to be a
hole in the filesystem structure, before we would even consider trying to
plug something in there. Once we know there is a hole, we want to
narrow down the list of candidates to fill it. If a candidate already lies
within a perfectly viable file, obviously we would not want to interpret
that as lost metadata. Unless the filesystem is really mess up...

That is about as far as I have got with the analysis. Clearly, much more
is required. Suggestions welcome.

Regards,

Daniel
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