[CentOS] Upgrade 3.4 --> 3.7 went awry: rpmdb hosed

Fri Jul 7 00:40:10 UTC 2006
Bart Schaefer <barton.schaefer at gmail.com>

I installed CentOS 3.4 from a CD image I'd burned a while ago, and
then attempted to update with yum to 3.7.  All the packages installed
OK, but at the very end of final cleanup I got an error message from
db4 saying to "RUN RECOVERY".

I did "rpm --rebuilddb" which may have been the wrong thing -- it
issued an error about "pages missing".  I then ran it again, and it
came back with no errors, but after rebooting (for the kernel update)
"rpm -qa" lists only a dozen packages or so, of which "rpm" is not
one, and "yum check-update" chokes, showing Null for $releasever and
the empty string for $basearch.

This was a brand-new system, so I'm thinking I'll just download the
3.7 ISOs and re-install, but on the off chance there's some other way
to recover from this I thought I'd ask.  There doesn't seem to be
anything missing other than a large chunk of the RPM database itself.