On Tue, 21 Jun 2016 15:18:38 +0000 Charles Duffy <char...@dyfis.net> wrote: > Couldn't one play with bind mounts to keep the absolute paths consistent on > both sides of the pivot operation?
Well I decided to accept "don't do that" approach. Also bind mounts are Linux specific. My main area of interest is s6 on my FreeBSD systems, but I try to understand Linux side of things as well. More over, I looked up once again FreeBSD pivot_root like thing. It is apparently called "reroot". It seems already present on my testing system. Info from reboot manpage implies that reroot kills even init: -r The system kills all processes, unmounts all filesystems, mounts the new root filesystem, and begins the usual startup sequence. After changing vfs.root.mountfrom with kenv(8), reboot -r can be used to change the root filesystem while preserving kernel state. This means Linux style pivot_root doesn't even happen, rerooted init gets clean state which seems much better even. Also although FreeBSD has nullfs mounts, those are not exactly same as Linux bind and it seems it doesn't need (*)dev helper at all. It appears to me, that /dev is always populated by kernel beforehand. "Don't do that" makes sense under these conditions. eto