Glasgow's DPM storage was configured to work in a reduced form: 6TB spread over 3 disk servers on Friday.
This took much longer than it should have because of an odd 'feature' in YUM: if, in yum.repos.d, a repostiory is named twice, then the second defintion is ignored. I had copied the CERN YUM repository defintions, and modified the baseurl to point to our local mirror. I then disabled the CERN repos. However, YUM just ignored my mirror definitions as it only read the, now disabled, CERN definition.
The YUM couldn't resolve any dependencies. Maddening!