Re: [gentoo-dev] recovering from corrupted vdb

[Rich Freeman <rich0@gentoo.org>]

On Thu, Nov 3, 2011 at 7:15 AM, "Paweł Hajdan, Jr."
<phajdan.jr@gentoo.org> wrote:
> I think we can't salvage much from a corrupted db (anything can happen,
> and the reporter mentions some code being present in the files), but at
> least "emerge -e world" or equivalent should be possible.

I'm not sure how portage handles not having ANYTHING in the vdb, but
wouldn't it at least be possible to just wipe out the entire directory
tree and then do an emerge -e world?  As long as the packages
themselves are working I would think that this should work.

The only thing I'm not sure about is that if portage thinks that
nothing is installed it might run into circular dependency issues.
Maybe we need an option to include dependencies in the list of
packages to install but not bail out on circular dependency issues
since the reality is that the packages are there.  Or, we need to give
the user a script to follow (maybe try to follow whatever the logic is
in catalyst since obviously that works).

If the packages themselves are corrupted then installing from binary
packages for @system would make sense.

That thread really sounds like some kind of filesystem corruption
issue, even if fsck doesn't report any problems.  Something like that
happened to me ages ago with some kind of mdadm+lvm+ext3 bug (an fsck
on one lvm partition destroyed data on a different partition).

A more intelligent solution would be to actually check the system for
consistency (file hashes, etc), and then just re-emerge the stuff that
is broken.

Rich