Hi Roger,
"Roger K. Wells" ROGER.K.WELLS@saic.com schrieb am 27.08.2009 14:26:17:
warning: rpmts_HdrFromFdno: Header V3 DSA signature: NOKEY, key ID
6b8d79e6
GPG key retrieval failed: [Errno 5] OSError: [Errno 2] No such file or directory: '/etc/pki/rpm-gpg/RPM-GPG-KEY-rpmforge-dag'
It means that you have gpgcheck enabled but the key to verify the packages' signature is missing. Go check yum.conf(5) and do a little research on how to properly configure the rpmforge repository (IIRC they have a RPM you can install which will do the magic)
Frank.