Dear all, I support dCache a HEP storage management product and on our wiki pages we recommend that people use your repositories for yum updates. I also have deployment testing scripts, which also break often with this error and since I don't change the settings I know the error is at least on many occasions server side. Today I one of my customers reported. yum update Repository sl-errata is listed more than once in the configuration Repository sl-base is listed more than once in the configuration Loading "kernel-module" plugin Setting up Update Process Setting up repositories glite31 100% |=========================| 951 B 00:00 ftp://ftp.scientificlinux.org/linux/scientific/44/SL/RPMS/repodata/repomd.xml: [Errno 4] IOError: HTTP Error 404: Not Found Trying other mirror. Cannot open/read repomd.xml file for repository: sl-base failure: repodata/repomd.xml from sl-base: [Errno 256] No more mirrors to try. Error: failure: repodata/repomd.xml from sl-base: [Errno 256] No more mirrors to try. The problem I suspect is caused by the SL repository indexes being updated on line. For the dCache yum repository I do this off line then rsync the information to my distribution servers. With this setup I have been unable to replicate this issue and non of my clients have ever complained of my repositories since we started with this policy. Glite and sl4 repositories get almost equal complaints but I suspect they deploy more updates per day and this maybe why I don't get them. I don't know how you manage the master SL repositories (maybe you also use rsync too) but some way to remove the occasional. IOError: HTTP Error 404 Would make life better for me. Regards Owen