Ian Jackson <ijack...@chiark.greenend.org.uk> writes:
> Ansgar Burchardt writes ("Re: support for merged /usr in Debian"):
>> m...@linux.it (Marco d'Itri) writes:
>> > Thanks to my conversion program in usrmerge there is no need for a flag
>> > day, archive rebuilds or similar complexity and we can even continue to
>> > support unmerged systems.
>>
>> Is there any use case that requires supporting unmerged systems?
>
> Someone has already mentioned mounting /usr ro. But one generally has
> to keep /etc rw. I don't think that the right way to address this is
> to make /etc a mount point.
Well, that is one of the reasons to move /{s,}bin and /lib to /usr: by
doing so mounting /usr read-only covers more static files.
/etc can live either on a rw root or on an extra partition (provided the
initramfs does the right thing). Note that /etc will *not* move to
/usr/etc.
> Anotheer example: I have a system which does a rather hackish NFS root
> boot. It has its own / but uses /usr from the fileserver. This has
> worked surprisingly well for a long time.
Hmm, such systems would probably need reworking with a merged-/usr. I
think if one does something like this, the system should treat its local
/ like a initramfs and just chroot into the nfs-provided filesystem.
One can mount /etc or other filesystems from the local system too if
needed.
Also for the general /usr-on-network and /-local case, it is unclear
what would need to be provided in /. As far as I understand with more
interesting setups, one needs to move more and more of /usr to / to
support that... Say for /usr-over-some-encrypted-network or
/usr-over-interesting-network-protocol or even /usr-over-wlan.
Ansgar
