Hi, I'm currently experimenting with Yum on a fresh CentOS 7 minimal install, and I'm getting some puzzling results. Here's what I did. 1. Install CentOS 7 from the Minimal CD. 2. Install 'deltarpm' and update all packages. 3. Install the "Core" package group: 'yum group install "Core"' 4. Install the "Base" package group: 'yum group install "Base"' 5. As expected, 'yum group list hidden | less' shows this: ... Installed Groups: Base Core ... 6. Now I remove manually all packages that were not present in the initial installation. I'm doing this using a script, which is supposed to get the system back to its pristine state. Various tests with 'rpm -qa --queryformat '%{NAME}\n' | sort > packagelist.txt' show me that this worked. 7. For mysterious reasons, 'yum group list hidden | less' still shows: ... Installed Groups: Base Core ... 8. When I try to reinstall the "Core" and/or the "Base" groups using 'yum group install "<Group>", I get the following result: # yum group install "Core" Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: ftp.pasteur.fr * extras: mir01.syntis.net * updates: ftp.pasteur.fr Maybe run: yum groups mark install (see man yum) No packages in any requested group available to install or update 9. As you can guess, the expected behavior was for Yum to *not* display the "Core" and "Base" groups as "Installed Groups" as soon as there was some stuff (if not downright all packages from the group) missing. Any suggestions on this? Cheers from the rainy South of France, Niki PS: you may wonder why I'm doing this. I may have to manage a situation where I have to deal with CentOS 7 installations that would first have to be pruned down without reinstalling everything. -- Microlinux - Solutions informatiques durables 7, place de l'église - 30730 Montpezat Web : http://www.microlinux.fr Mail : info at microlinux.fr Tél. : 04 66 63 10 32