As mentioned in the comments, this is a harmless warning that informs you that a package has been installed or removed directly using the rpm
command instead of yum
. The difference is that yum
is smarter in automatically resolving dependencies, and it is the default way of keeping the package-management DB on your system up-to-date (hence the warning).
See Execution of yum leads to "Warning: RPMDB altered outside of yum." for an official explanation of the message on the Red Hat Customer Portal.
To get rid of the warning, run:
# yum history new
See also yum or rpm, which contains further explanations and links to Red Hat documentation about both Yum and RPM.