>There's no point developing our own partitioning scheme; if we want a
>better partitioning scheme, we should just use the BSD disklabel format.
>The real problem with any alternative scheme, though, is that it becomes
>incompatible with Dos/Windows/NT systems, and many Linux users need to
>be able to coexist with them. The BSD systems have developed some
>schemes where two partition tables (one for their own and one for
>DOS/Windows/etc.) coexist, but there's lots of potential for lossage if
>the two partition tables get out of sync. (For exampe, if a fdisk
>program under Linux or Windos which doesn't know about the BSD label
>modifies the partition table; now the BSD label is out of sync.)
The patch for OpenBSD disklabels I managed to get into 2.2.0 includes a
small failsafe mechanism.
- recognizes that OpenBSD disklabels may have up to 16 partitions,
- merge BSD`slice' partitions with the linux-side view of the disk,
- don't try to add BSD partitions that overlap with the linux-side partitions.
It's already a first step in that direction.
What's still missing is the ability to deal with several distinct disklabels
markers on the same disk, the ability to check the semantics of disklabels
further (a, b, c, d partitions. Watch out !!! OpenBSD has simplified that
scheme: c comprehends both the whole disk and the area included in the
disklabel).
What I also don't know is what should be done when you get an incoherent view
of the disk. Trust the linux-side ? Sounded like the simplest way to do
things... I don't see how panicing at such an early point would help, for
instance.
If you want to play safe, all decent OSes documentations recommend to use their
own fdisk-like program to edit the area of the disk they're concerned about:
use linux's fdisk for linux partitions; use OpenBSD's fdisk for OpenBSD
partitions.
That's sensible advice: as much as it would be convenient to have one single
program that would deal with all partitioning schemes, it is a maintenance
nightmare. Who would like to be in charge of synching linux/netbsd/
freebsd/openbsd fdisk so that it keeps in tune with all those OSes...
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