Hello, Thanks to KB for the suggestion. The problem was indeed related to the file /etc/yum.repos.d/CentOS-Base.repo A number of the sections (e.g. base, updates) had been set to enabled=0. When I commented out these lines, the yum updates worked fine... Thanks, John. Karanbir Singh wrote: > On 18/06/2010 12:04, John Kelly wrote: > >> I'm having a yum problem updating a system on Centos 5.3, 64-bit ... >> i.e. 'yum update' returns "No Packages Marked for Update". Problem >> appears to be related to connecting to the mirrors where the >> repositories are located but I could be wrong in that. What's confusing >> me is that I have another system (Centos 5.5, 32-bit) that's working fine. >> > > Try hitting yum with a -d7; its hard to tell from the very little pasted > data as to what the issue might be. At the very least, you dont have a > valid CentOS-Base.repo in your /etc/yum.repos.d/ directory and/or your > /etc/yum.conf has been changed. To check for both of those: rpm -V > centos-release ; should tell you. > > - KB > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos > >