On Sun, Mar 07, 1999 at 01:14:25PM +1100, Richard Gooch wrote:
> Adam Sulmicki writes:
> > Richard Gooch writes:
> > dos has limit on 4 (3) primaries, so it came up with idea of extended
> > paritions. I though there was limit on 4 extended, but I could be wrong=
.=20
> > If we want stay MS-dos compatibile, we want to use ms-dos style paritio=
ns
> > as primary partitions.=20
Yes, there is a limit of 4 pimary partitions. One of them can be an extended
partiotin and contain logical drives. These are not managed by having a
certain sector reserved to hold its info (like the primary partioins in the
first sector (MBR)), but rather linked by a sort of linked list, and so
there is almost no limit. Operating systems put limits; Linux currently
supprts up to 63 partitions per IDE disk, meaning 3 primary, one extended
containing (63-4=3D59) logical drives. For SCSI disks it's only 15 partitio=
ns.
The limits are caused by the device numbering ...
> > Other styles (like bsd) don't have limit on primaries, so there is no
> > need for extended paritions. Consequently there is no support for=20
> > "slices" inside of paritions.
=2E.. but you can do loop device tricks, which is something completely
different, of course, but might serve similar needs.
Having slices containing subslices containing subsubslices containing ....
reminds me of the filesystem hierarchy. Just the fs is much more flexible,
as the sizes of the directories is not fixed in advance causing headache to
change it.
I don't see much reasons for high levels of subslicing your harddisk. You
certainly want to protect different OSes from killing others and maybe some
subsystems, like the /home tree, from filling up important space, but that
can be done with the current scheme for most cases, I think.
Regards,
--=20
Dipl.Phys. Kurt Garloff <kurt@garloff.de> [Dortmund, FRG]
Plasma physics, high perf. computing [Linux-ix86,-axp, DUX]
PGP key: see mailheader / key servers [Linux SCSI driver: DC390]
--NMuMz9nt05w80d4+
Content-Type: application/pgp-signature
-----BEGIN PGP SIGNATURE-----
Version: 2.6.3in
iQCVAwUBNuRFAhaQN/7O/JIVAQEVHwQAjGlK3HReyCJPlf90wXIX5skSHMkhw5Hp
Kzk0tosDP4sF5EWZFxqiGiE+m5/1AtbSlTR7hXfNVlehd2kgx7Fm8O9Y6cSbQXmZ
/JdweIBA8jDGo+NwKa+GWSsd2MuebAWNXxABrLnDz1NNRbDCbXIXPps8zjrgbS2t
ZNJlG7DERmY=
=nGDa
-----END PGP SIGNATURE-----
--NMuMz9nt05w80d4+--
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/