Re: [woody,debinst] Interim filesystem
Bruce Sass wrote:
>
> On Mon, 19 Jun 2000, bug1 wrote:
> > Bruce Sass wrote:
> > > On Sun, 18 Jun 2000, bug1 wrote:
> > > > How and Interim filesystem might work (as i see it)
> > >
> > > Why have an interim fs?
> >
> > 1) To get around any space limitations presented by the boot medium, or
> > ramdisk.
> > It is delaying the partitioning process till later on after we have
> > lots on space available to us.
> > There are lots of different things we can consider doing if space isnt
> > the primary limitation.
>
> What is the advantage to delaying partitioning, get it out of the way
> fast and you have the whole harddrive to play with.
>
If you get it out the way first, then you limit how powerfull it can be.
If we delay partitioning till after the installer has accessed the
debinian binary archive then partitioning tools can be taken from the
archive rather than being included with the installer.
We can access the debian binary archive prior to partitioning with a
traditional installer, but then we have the problem of not necessarily
having enough disk/memory space to be able to unpack them, hence an
interim filesystem
If we can have anything from the debian archive prior to partitioning we
can get binaries to do filesystem resizing, LVM, raid, without
includeing them in the installer.
We could also delay partitioning till after a hardware detection stage
which gives time for kernel modules to be inserted incase any hardware
that should be repartitioned wasnt detected by the boot kernel.
In a modular installer we would be much less dependent on extracting
debs from the debian archive as all the required binaries could be in
the modules rather than extracted from the debian archive.
Having the binaries in the modules would make the modules much larger
them if they were just differnt configuration files/scripts, and then we
also have to sort out libraries.
If we have lots of space we can use full libraries
Having LVM, RAID and Resizing tools available when doing the
partitioning would mean there are no limits to how you choose to
partition your system, and you could most likely install without having
to first backup the contents of a partition prior to the install which
destroys it.
Where im coming from is that i consider partitioning to be (probably)
the most important part of the installation, its much harder to
repartition after the install than it do any other configuration.
Thats my experience anyway.
> I was thinking of a monolithic installer core, modularized like the
> kernel is for `maybe needed' functions... very small footprint, maybe
> even totally in memory.
>
If we can have LVM, RAID and Filesystem resizing tools available for
partitioning using this methods i would be just as happy.
> > 2) It adds a seperation layer between what we are installing from and
> > what we are installing to.
> >
> > To enable non linux installs, e.g. Debian/Hurd (or Debian/bsd, or
> > Debian/plan9 if they eventuate)
>
> Hopefully the installer will not be Linux specific. i.e., one could use
> it to install Hurd, etc., just by having the proper modules available.
>
Yea, true.
> > For all those cases the interrim filesystem would always be Linux, and
> > the linux interim filessytem would provide what is needed to install and
> > configure the local hardware (partitioning etc), the final os kernel and
> > then can just be copied across and activated on reboot.
> >
> > It adds a seperation layer between what we are installing from and what
> > we are installing to.
>
> I'm not sure why that is a good thing.
>
> > Was i convicing ?
>
> No, but don't sweat it, I may just have strange ideas about... :)
>
Fair enough, constructive criticism is always a good thing.
Glenn
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