yum Error:rpmdb open failed

This is how I fixed my problem.

You may fix this by cleaning out rpm database. But first, in order to minimize the risk, make sure you create a backup of files in /var/lib/rpm/ using cp command:

mkdir /root/backups.rpm.mm_dd_yyyy/
cp -avr /var/lib/rpm/ /root/backups.rpm.mm_dd_yyyy/

The try this to fix this problem:

# rm -f /var/lib/rpm/__db*
# db_verify /var/lib/rpm/Packages
# rpm --rebuilddb
# yum clean all

And finally verify that error has gone with the following yum command

# yum update