> On Apr 6, 2016, at 4:55 AM, James Le Cuirot <ch...@gentoo.org> wrote: > > On Wed, 06 Apr 2016 09:42:04 +0200 > Alexis Ballier <aball...@gentoo.org> wrote: > >>> This was invented in Solaris and copied by RHEL. The upgrade >>> path for the /usr merge on those systems is a complete >>> reinstall. Upgrading from RHEL6 to RHEL7 this Solaris 10 to >>> Solaris 11 is not supported. The reason being that there are >>> ways of configuring the system boot process with the original >>> layout that break if you try using scripts to migrate to the new >>> one. A USE flag for the /usr merge that is off by default would >>> allow us to have both worlds without putting any systems at >>> risk. >> >> that's what i'm actually more worried about: the fact they failed to >> have a proper upgrade path doesnt mean it is impossible, just that it >> is not easy. > > What about Fedora? This system I'm on now started as Fedora 16 and has > been upgraded step by step to 23. /bin, /lib, /lib64, and /sbin are > symlinks but I'm pretty sure it didn't start out that way. I knew the > change was coming but when it actually happened, I didn't notice for > quite a while.
The common case can be done by automated scripts. The case where the system is configured to mount /usr after init has started is not. In Fedora's case, they tell users to expect upgrades to break things, so the people bitten by it at least had been warned of breakage before they installed Fedora. > > -- > James Le Cuirot (chewi) > Gentoo Linux Developer >
