seth writes:

rpm –rebuilddb
Then go to /var/lib/rpm and make sure __db* files are gone.

For me it was the other way round, just a few days ago. I'm so used to RPM being totally broken with respect to locking, and always hanging up, that it's a habit now to just kill RPM (with ^Z, kill -9 %1, because it doesn't even respond to ^\, ffs), rm -f /var/lib/rpm/__db* and then run it again.

Unfortunately, I stupidly did this (and installed more packages) while 'yum update' was running. Not very clever of me, I suppose -- almost an ESR moment. But not quite, because I really should never have been forced into the habit of removing those lockfiles manually; that RPM bug really ought to have been fixed a number of years ago.

Thankfully, although I was very scared for a moment, the database rebuild was successful. I then logged into another remote machine to update it, and what did I find? 38 copies of the nightly cron job all blocked on rpmq because of the same crappy locking issue. And I had to think really carefully before I removed the __db* files that time :)