stefan and okuji discussed breaking the four primary partitions
limit; the need for it; concerns about hacks; and a couple ways
to address the issue.
i wanted to comment, offer my help, and ask for a couple things
(at the end). i apologize in advance for the (inadvertent) puns
that lie ahead.
--
i believe this may well be a bigger issue than may be inferred
from the subject line stefan chose. the four primary partition
limit is somewhat of a headache for non "obscure" OSes.
i think this issue is growing very rapidly, because the size of
a new hard drive has reached a point where this issue comes to
a head.
--
i think this might be an opportunity for GRUB to again show
leadership, and to help out the GNU cause to boot.
given that this issue will be particularly hot with what is
arguably a key constituency for future Hurd converts, namely
those who want to try out lots of OSes, it really does make
a lot of sense for GRUB to address this if it can be sensibly
addressed, and especially if it would be easy.
--
after searching high and low, and trying out various techniques
and software (commercial, free as in beer, free as in speech)
designed to get around the four partition limit (e.g. bootit,
symon, ranish respectively), i have tentatively arrived at the
same conclusion as stefan, namely that the "best" solution is
to alias logicals to primaries.
there are several reasons for this, but some primary ones are:
o breaks compatibility in a relatively minor and clear way.
after aliasing, some partitioning related software will
print a warning message, some such software will refuse
to run, but i've not found any software that has gotten
dangerously confused, even junior programmer m$ stuff.
if a user wants to run a piece of software without the
overlap message/issue, simply reboot, remove the alias,
and reboot again.
this relatively gentle breakage is in contrast to the
problems created by the other solutions i've seen. all
the software listed above hide partitions from the mbr,
which means other existing software can unwittingly
overwrite areas of the disk it should not.
o requires a relatively simple addition to mbr/boot managers.
o requires relatively little work to update old software.
all that one has to do is to allow that primary partitions
may overlap logicals. if sanity checking is still desired,
confirm that the primary has exact overlap with a logical
of the same fs type.
--
altho i am not really in a position to help with programming
(for example, i don't know C), i wanted to go on record that
i tentatively support stefan's suggestion, can contribute to
trying this out with mixed OS setups using a whole bunch of
OSes, can help with any doc issues that arise, and could help
monitor this list to answer related questions.
--
finally, i have a couple of favors to ask:
okuji: thanks for grub, and i agree with your overall concern
about hacks, but what about adding a link to stefan's patch
somewhere, maybe an experimental extensions section of the doc?
stefan: i would really appreciate a copy of your modified grub.
i understand that all risk is mine. a linux binary that is
compatible with debian 2.1 or toms root boot disk would save me
some headaches right now (i have never compiled stuff, nor
applied a patch, before), but if you don't have such a thing,
a copy of your patch would still be very much appreciated.
tia.
--
ralph mellor
