On Mon, 24 Dec 2012 16:06:27 +0800 Mark David Dumlao <madum...@gmail.com> wrote:
> On Mon, Dec 24, 2012 at 9:27 AM, Walter Dnes <waltd...@waltdnes.org> > wrote: > > On Sun, Dec 23, 2012 at 08:39:41PM +0000, Neil Bothwick wrote > > > >> You are only considering the case of /usr being on a plain hard > >> disk partition, what if it in on an LVM volume, or encrypted (or > >> both) of mounted over the network? All of these require something > >> to be run before they can be mounted, and if that cannot be run > >> until udev has started, we have been painted into a corner. > > > > I agree that there will always be a small number of corner-cases > > where an initr* is required. What annoys me, and probably a lot of > > other people, is the-dog-in-the-manger attitude > > http://en.wikipedia.org/wiki/The_Dog_in_the_Manger where some people > > seem to say "If my weirdo, corner-case system can't boot a > > separate /usr without an initr* then, by-golly, I'll see to it that > > *NOBODY* can boot a separate /usr without an initr*". > > This is misleading in two ways. > > 1) You're talking as if having a functionally merged /usr and / system > (i.e., many programs needed by the sysad to fix a non-booting system > are in /usr, and programs in /usr will break if /usr is not in sync > with /) is a weirdo corner case. It is NOT. It is very likely how the > vast majority of Linux systems on the planet work. Separate /usr is > itself the weirdo corner case. It was in fact a weirdo corner case > since day 1. > 2) You're talking as if Lennart or whoever is breaking into your > systems and actively preventing you from customizing it to boot a > separate /usr. If this is the case you _really_ need to change your > ssh keys, they wiped that vulnerability a couple years ago. > > Nobody's preventing you from building a custom system that cleanly > separates / and /usr. But hey, don't pretend that even Gentoo does it > correctly. Besides the equery tests in this thread, I've never > personally confirmed that any other distro does - and Fedora cleanly > admits that they don't. > The ultimate weird corner case is having a separate / and /usr so the either of these two thing can happen: a. there's enough $STUFF in / to fix large-scale errors b. there's enough $STUFF in / to mount /usr ro over NFS (as in for a terminal server) a. is fixed by just using what all sysadmins use anyway - a proper rescue disk built for that specific purposes (instead of trying to get half a system to do it for you) b. is resolved by mounting /, not /usr. It's a terminal server, so the only thing not under full user control is ~. There is no point in having half the system local and the rest of it remote, just mount everything remotely. And if it's a terminal server, it will have a real sysadmin, someone who can maintain the code needed to get NFS up at boot time. If the mount of / breaks, the solution is a. Are there any other cases, apart from emotional attachment based on inertia, where a separate / and /usr are desirable? As I see it, there is only the system, and it is an atomic unit. -- Alan McKinnon alan.mckin...@gmail.com
