switching discs during install

Mike Clarke jmc-freebsd2 at milibyte.co.uk
Sun Sep 7 09:22:41 UTC 2008


On Sunday 07 September 2008, James Strother wrote:

> That said, I still think that as long as the freebsd foundation
> distributes CD images it would be worthwhile to make them as
> effective as possible. Actually, even if the install were moved to a
> DVD, the ordered install I proposed would still improve the
> situation.  When the packages are haphazardly ordered on the disc,
> the CD/DVD reader is forced to perform a large number of seeks that
> dramatically reduces data throughput.  When they are read in order,
> read rates should be much better.

They might not be as haphazard as you suggest. ISTR once reading that 
the CDs were arranged with the most popular packages on the first CD so 
that you would only need to download disk 2 (and 3) if you wanted some 
of the less common packages. With your suggested layout it's quite 
likely that a package which most of the others depend on would be right 
down at the bottom of the list with the result that you'd invariably 
need to download all 3 CD images.

I think the best way to avoid the need for frequent CD switching would 
be for sysinstall to sort the list of selected packages into CD order 
before installing them. I imagine this would require some changes to 
pkg_add to prevent it from installing dependencies and I expect the 
possible benefits would not be considered to be sufficient to justify 
the effort.

-- 
Mike Clarke


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