Date: Mon, 14 Jun 2004 16:05:47 +0200 (CEST) From: Soeren Straarup <xride@x12.dk> To: Poul-Henning Kamp <phk@phk.freebsd.dk> Cc: geom@freebsd.org Subject: Re: GEOM class idea... Message-ID: <20040614160301.Y81182-100000@x12.dk> In-Reply-To: <87385.1087146851@critter.freebsd.dk>
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On Sun, 13 Jun 2004, Poul-Henning Kamp wrote:
>
> OK, here is one of the more nasty ideas for a GEOM class:
>
> Many of us read CD's into iso images, stick them on a harddisk and
> mount them from there when we need to access them. This usually
> costs us a md(4) vnode gadget, and that is really a waste.
>
> Write a GEOM class which is a slicer, but it needs to work on CD9660
> image headers as metadata, and work the following way:
>
> Read in the first ISO image onto our archive disk:
>
> =09dd if=3D/dev/acd0 of=3D/dev/ad8 bs=3D2k
>
> On close, the disk is tasted, and our "geom_cdarch" class finds a
> valid CD9660 volume description and attaches to the disk.
>
> It extracts the image size from the CD9660 descriptor (offset 0x8050,
> 32bitLE. Repeated at 0x8054 as 32bitBE) and creates a slice with
> this ISO image in it.
>
> Since there is no valid CD9660 descriptor on the disk right after
> this image, the remaining free space gets put into a special
> slice ("ad8.freespace").
>
> To read in the next ISO image:
>
> =09dd if=3D/dev/acd0 of=3D/dev/ad8.freespace bs=3D2k
>
> On close the geom_cdarch class looks for a valid CD9660 volume and
> if it finds one, creates a new slice and recreates the freespace
> slice with the space now available, and we can repeat the process
> until we run out of space.
>
> Any takers ?
>
>
> --
> Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
> phk@FreeBSD.ORG | TCP/IP since RFC 956
> FreeBSD committer | BSD since 4.3-tahoe
> Never attribute to malice what can adequately be explained by incompetenc=
e.
Question: Will the iso 'fs' be bootable and listed by the boot manager?
That is if the iso is a bootable iso image
Best regards S=F8ren
Soeren Straarup | aka OZ2DAK aka Xride
FreeBSD wannabe | FreeBSD since 2.2.6-R
Don't let your brain be in idle to long
it might get stuck there
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