IBook G4 and FreeBSD 9.0-RC2: unable to create four slices on hard drive?

[Marcel Moolenaar]

On Nov 17, 2011, at 7:32 AM, Andrey V. Elsukov wrote:

> On 17.11.2011 16:04, Andrey V. Elsukov wrote:
>>> entries: 3
>>          ^^^ - this is why you get this error.
>> 
>> This information is from the metadata.
>> I'm not familiar with APM partition table, but may be Marcel can suggest something?
> 
> So, i wrote a small patch. It reserves first 14 sectors to be able
> create new partitions. Also, we can add a check that is there some free
> space to extend APM when we are trying to add new partition.
> Marcel what you think about that?

I don't think it's a good idea for the simple reason that if I
want to split the first partition into 2, I may find that I
cannot recreate the first at the same offset as the one I
deleted, because gpart adjusted the first usable sector.

The fundamental problem here is that the APM only has 3 entries
usable for partitions and since we don't have a gpart method
for extending the partition table, users just need to destroy
and recreate.

Which is another reason why no partition scheme should have
magic behaviour: if we later add a method of extending the
partition table, any magic behaviour is likely to be in the
way.

In general: don't look too much and/or too often to quick and
dirty "magical" work-arounds or solutions. Understand the
problem and be willing to say that we don't have a solution
for it (yet). Keep the schemes simple and straight-forward
so they all behave the same with roughly the same limitations
and features.

FYI,

-- 
Marcel Moolenaar
marcel at xcllnt.net