> > > Many modern systems have their /etc/resolv.conf files autogenerated
> > > at runtime with DHCP, PPP or so on. Thus, storing that file in /etc
> > > seems no longer correct as that directory may be mounted read-only.
> > 
> > While i don't disagree on that move i'm suspocious about the
> > whole /etc/ ro mode. I don't think it's usable right now. Is your
> > main goal to make it working by default?
> 
> I would really like to do so but I don't think I have enough power to
> do so. Right now, I'm running one machine with read-only root and
> resolv.conf was the only really problematic file for it.

Ah, i see.

> > - /etc/blkid*
> 
> That one's udev specific? I guess it could be moved as well.

It's a blkid(8) cache to mount stuff by uuid/label and guess FS.
Used at least by udev rules and stuff linked against libblkid (fsck.*).
Both can be triggered at any time later after boot.
blkid(8) can work w/o cache.

> > - /etc/adjtime?
> 
> I was never sure what this is for. Does it really need to be updated
> randomly during runtime or once is enough?

It's saved/restored by hwclock(8) when system shutdowns/starts.
In theory hwclock can be reran time to time on running system,
but i don't think it's common. In-kernel copy of clock skew is expected
to be maintained by ntp-alike daemon.

-- 

  Sergei