Am Donnerstag, 20. Dezember 2012, 11:45:34 schrieb Mark David Dumlao: > On Thu, Dec 20, 2012 at 2:42 AM, Volker Armin Hemmann > > <[email protected]> wrote: > > with redhat's push to move everything into /usr - why not stop right there > > and move everything back into /? > > I originally thought this way, but they actually reviewed the > technical and historical merits for all the use cases and and found > /usr to be superior. Straight out of the freedesktop wiki: > http://www.freedesktop.org/wiki/Software/systemd/TheCaseForTheUsrMerge > > 0) If / and /usr are kept separate, programs in /usr can't be updated > independently of programs in /, because the libraries they depend on > might break compatibility. If the binaries and libraries were *all* in > /usr, then the entire system's binaries would always be consistent > regardless of where /usr were sourced from (config files in /etc, > however, would still break).
not a problem at all if everything is in / and /usr doesn't even exist anymore. > 1) There is historical precedent in Unix for /usr-centric systems, > notably Solaris. so what? historically we lived in mud huts and used flintstone knives. > 2) If /usr were separated from /, then /usr could be mounted > read-only, with / being mounted "normally". Which makes sense, as / > does have bits that are meant to be read-write. really? once upon a time I was told mounting / ro and /usr rw was a GOOD THING to do. I ignored that the same way I ignore it the other way round. With bind mounting and stuff, you can make single directories rw.. so what is the matter? > 3) Most software packagers write their binaries to a PREFIX defaulting > to /usr/local, or /usr, as opposed to /. Determining which ones belong > in / or /usr can sometimes be dependent on the distro and/or sysad. > But since more of them default to /usr, if everything were in /usr > it'd be a saner default. so what? PREFIX can be changed. Set it to /local if you want. Or /var/local. Or /my/happy/place/local. > > (0) basically says that keeping them separate only works as intended > if the both the sysad and the distro upstream work together for their > shared /usr mount. In many cases, however, sysads have to do a lot of > working around and careful planning to get /usr mounted remotely. > (1), (2), and (3) provide advantages to mounting the binaries and > libraries separately from the / filesystem, which mounting them as > part of / does not provide. no, not really. No. -- #163933
