How to Fix Yum Error: database disk image is malformed

Possible Cause For Error

Yum is a well known tool used for installing packages on RPM based Linux distributions. It is most widely used package manager on Redhat Enterprise Linux, CentOS and Fedora operating systems.
Any other operating system derived from these distributions also use Yum for the installation, update or removal of software packages.
If you are encountering following error message while updating or installing any packages, its obvious that something bad has happened to Yum.

Error: database disk image is malformed

It usually occurs once “yum update” process is interrupted, quite possible that your system went powered off during  “yum update” process and it left yum database in a corrupt state, all we need to do is to clean and repair yum database to fix the error.

Fixing this Yum’s error

There are few steps to resolve this error, all pretty simple.

Clear Yum Caches

Clear yum cache by running the following command. It will ensure to remove entries from /var/cache/yum/ directory
Please note that it will not effect any of your currently installed packages. Pretty safe command to run

yum clean all

Clear Yum’s XML meta data by running the following command:

yum clean metadata 

Run following command to clear the cached files for database.

yum clean dbcache

It is important to clear Yum’s make cache, use following command:

 yum makecache 

Rebuild RPM Database

As the last step, make sure to rebuild your system’s RPM database. Run following two commands to achieve this.

mv /var/lib/rpm/__db* /tmp 

rpm –rebuilddb 

How to fix: ERROR 1045 (28000): Access denied for user ‘root’@’localhost’ (using password: YES)

Open your terminal and type mysql -u root -p Enter your password. Hopefully your MySQL is logged in now.