[X-Unix] HD with both OSX- and linux-readable partitions

[William H. Magill]

On 06 Jul, 2004, at 17:49, Warren Pollans wrote:
> I'd like to put an old 40 GB HD into an external usb/firewire 
> enclosure for use by both OSX and Linux.
>
> Lots of questions.
>
> Is this possible?  Create two 20 GB partitions (1 hfs+, 1 ext3)? It's 
> not necessary that the files created by one OS be accessible to the 
> other OS.
>
> Is there one fdisk that can create both types of partitions?  Or will 
> I have to make one from OSX and one from linux?  If so, will the 
> partitions of one OS be recognized by the other?
>
> Is the order in which they're made or the order in which they appear 
> on the HD important?
>
> I could just do it and experiment, but I thought I'd ask first.

Hmmm -- never tried this combination.

However, with Tru64 Unix (Alpha) and Linux (Suse and supposedly 
RedHat), the trick was to format the disk using Tru64 Unix's tools as 
it created disk labels which Linux could read (BSD style labels), but 
Linux did not create BSD style labels which Tru64 Unix could read. [In 
this environment one could flip back and forth - booting either 
partition. And, Tru64 could read and mount the Linux disk with no 
problems as well as vice-versa.] I have an XP1000 which is "dual 
booted" between Tru64 and Susie.

sooooo ... extrapolating that since Darwin is FreeBSD, one would guess 
that by using the disk formatting tools from Darwin, it might be 
possible to write labels which Linux can read.

The order issue is actually the only important thing -- the bootstrap 
information is where the two label formats differ significantly. ... 
BSD actually being the less flexible since it represents the older, 
"backwards compatible" format.

T.T.F.N.
William H. Magill
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