yum, rpm and duplicate versions

Apparently, when doing "yum update", and it fails miserably, you can end up with duplicate versions of packages in the RPM database. This seems harmless, but is annoying. yum provides a tool to check for this, but I was not able to find anything that would automatically repair it. So here's a little tip:

$ yum check duplicates | awk '/is a duplicate/ {print $6}' > /tmp/DUPES
$ yum remove `cat /tmp/DUPES`

 Of course, before you remove the dupes, make sure to examine the tmp file (/tmp/DUPES) and make sure it looks ok.
Update:
There seems to be a command to do this, package-cleanup has an option for it. E.g.

$ package-cleanup --cleandupes

However, testing this command on a second box having the same problem gave bad results, it seems to have uninstalled the "real" packages too.

Creating a Local Yum Repository Using an ISO Image

Sometime , our server internal can not access internet . we able to  create respository local for use yum command .

1. Transfer the removable storage to the system on which you want to create a local yum repository, and copy the DVD image to a directory in a local file system.

2 . Create a suitable mount point, for example /mnt/ISO

3. use the “mount” command to mount an iso
[root@kilo ~]# mount -t iso9660 -o loop V77197-01-OracleLinux-6U7.iso /mnt/ISO/   

4 . In the /etc/yum.repos.d directory, edit the existing repository files

[OL67]
name=Oracle Linux
baseurl=file:///mnt/ISO
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY
gpgcheck=1
enabled=1

5. Clean up the yum cache

 yum clean all

6. Test that you can use yum to access the repository. 

yum repolist