Inode wastage [was: dac960 devices on boot-floppies]

[Erik Andersen <andersen@xmission.com>]

On Mon Nov 15, 1999 at 03:55:26PM -0500, Adam Di Carlo wrote:
> 
> >I did essentially the same thing for Compaq SMART2, on /dev/ida/c0d0.
> >I posted the diffs on debian-boot on Nov 3 (archive/latest/4990), but
> >I imagine no-one had had the time to read it.
> 
> Yes -- we're getting the core system in shape right now, then we're
> going to take a closer look at what extra devices we can easily
> support.  Note that even *inodes* on the rescue disk are in short
> supply.
> 

On the subject of inodes... We have a very limited supply of inodes to
spread around. So I propose the following solution for not squandering
inodes on /dev/entries.  We create a /dev on the boot floppy with _only_ 
the minimum set of devices needed to boot the floppy.  Then we add
a platform specific dev.tgz to the boot floppy.  For my potato system,
the ~1100 devices in /dev when compressed as a tar.gz take up ~12k.  
Then on boot we have something like this in /etc/init.d/rcS:

    # fit /dev/* inodes into 100k ramdisk.  This should 
    # leave ~6k free with the ~1100 devices on my potato system.
    #
    dd if=/dev/zero of=/dev/ram1 bs=1k count=100
    /sbin/mkfs.minix -n30 -i 1200 /dev/ram1 100
    mount /dev/ram1 /mnt -t minix -o rw
    zcat dev.tgz | tar -xf -
    umount /dev/ram1
    mount /dev/ram1 /dev -t minix -o rw

This simplifies the problem of needing to fit feasible /dev entries
into the floppy and avoids the major inode wastage problem.  When given
the choice between wasting ramdisk space and wasting floppy disk space,
I'd vote for wasting some ramdisk space to store /dev.

Sound ok?

 -Erik

--
Erik B. Andersen   Web:    http://www.xmission.com/~andersen/ 
                   email:  andersee@debian.org
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