On Thu, Jul 06, 2006 at 05:40:10PM -0700, Bart Schaefer enlightened us:
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.
Coincidentally, there is a thread regarding this happening right now over on the nahant mailing list:
https://www.redhat.com/archives/nahant-list/2006-July/msg00011.html
Matt