On 10/27/2011 08:35 PM, Chris Adams wrote: > Once upon a time, Chris Adams<cmadams@xxxxxxxxxx> said: >> One big question though: can RPM handle such a change? IIRC, when the >> switch from /etc/rc.d/init.d to /etc/init.d was made, initially >> everything was going to be moved and the old paths symlinked for a few >> releases. However, there was some problem with RPM that couldn't handle >> switching an existing directory to a symlink, so that change was reduced >> to introducing /etc/init.d as a symlink. How will upgrades be handled >> if this feature goes through? > > I haven't seen this part addressed, and the more I think about it, the > more I think it may be a show-stopper for upgrades. > > IIRC the problem is that if there are any files in /bin, RPM can't > replace the directory with a symlink. There could be files from > third-party RPMs, Fedora RPMs that have been retired but people still > have installed, or from local changes/customizations. > > There is also a problem with the order things are done. RPM can't > replace /bin until all RPMs such as bash are updated to versions using > /usr/bin, but as soon as you install that bash, /bin/sh %post scripts > are broke until /bin is symlinked. > > For example, if you use the old-style network initialization (instead of > NM), the way to do pre/post config per interface is with > /sbin/ifup-pre-local and /sbin/ifup-local. If an admin has created > those files, RPM can't replace /sbin with a symlink to /usr/sbin AFAIK. > > This would also apply if somebody added firmware manually to > /lib/firmware or built a local kernel and installed modules to > /lib/modules. > > The only way I see to make this work would be to put a change directly > into anaconda (before it starts installing RPMs), but then you'd break > anybody that tried to "yum upgrade" from an older release (and there are > always people that do that). Any anaconda work-around for this would > also have to handle filename conflicts among locally-created files (e.g. > /bin/foo and /usr/bin/foo). > The strategy is: - Replace binaries in /bin /sbin /usr/sbin /lib /lib64 with symlinks to their counterpart in /usr. Symlinking is done in rpm %post. Symlinks are part of the filelist with %ghost. - As soon as one of these directories _only_ contains symlinks, it can be removed completly and replaced by a symlink. - The removal of the directories can either happen after the upgrade via anaconda, or within the initramfs while booting or in shutdown. - Fresh installations will get the toplevel symlinks immediatly and no %ghost symlinks are created Read the rpm snippet on the feature page, please. -- devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/devel
