Re: /var like dir accessible early in boot sequence
Tim Dijkstra <email@example.com> writes:
> We need a directory, which is accessible very very early during boot.
> It has some files in it which are regenerated at regular intervals, but
> not (necessarily) during boot. Actually we know generate it during
> runlevels 0 and 6.
> For know we put this in /lib/$package. I'm not sure this OK, because it
> means we will write to / also when we're not installing
> packages. /var/lib seems better, but that is not available that early.
> If it is really necessary we could generate the information during
> boot, so maybe /lib/init/rw?
> grts Tim
/lib/$package is obviously wrong. That might not be writable during
boot or even ever (apart from package installation time).
If you need the info during boot before networking and /var is there
then it must be on / or generated and you must not write to / outside
of package installation time.
So do you see any other choice but /lib/init/rw?
If generating that info is expensive then you could check for
/var/lib/package/. If it doesn't exist then you fallback to
/etc/init/rw/ and generate the info. Later in the boot process you can
move the info from /etc/init/rw to /var/lib/package or just delete it
if /var/lib/package needs no update.
Many people have /var on / or at least as local filesystem. Depending
on how early you need the info and depending on the setup /var might
just be there saving you the time, or it might not. It must be
possible to use with /var on nfs or the like and / read-only. So go