I'm still experiencing the problem, even with the new glibc.
This morning however, one redhat engineer declared the problem to be 'harmless'. Additionally, the engineer indicated the problem will be resolved in RPM version 4.3 (rh9 ships with RPM version 4.2).
With that, bug reports related to the rpm/db4 issue were abruptly closed.
The following excerpts are from
http://bugzilla.redhat.com/bugzilla
From case 83281:
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There are too many descriptions of varying problems here
for me to parse "reproduce this one". (name): could you open
a different bug and describe your persisting problem? If
just the error message
error: db4 error(16) from dbenv->remove: Device or resource busy
that's a known (and harmless) error message with --rebuilddb.
Otherwise, I'm gonna close this bug because there's too many
different problems here to sort out. Feel free to reopen other
new bugs if you still have problems.
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From bugzilla case 88273:
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Yes, there is an error message displayed after --rebuilddb.
The message is harmless, there is no problem here.
This is a known issue and will be fixed in rpm-4.3.
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Anyway, you get the gist: "harmless", "no problem here", "will be fixed in rpm-4.3". Ta-ta.
Well, that sure was a load off my mind.