Partitioning question

[Gary W. Swearingen]

Ouattara Oumar Aziz <wattazoum at gmail.com> writes:

> Here is the actual state of your disk referring to the block mapping
>
> <--------------/dev/hda1------------------------------------->
> <--/dev/hda5--><---/dev/hda6---><--/dev/hda7--><--/dev/hda8-->

Even that is something of a fiction, it seems.  According to
http://www.ata-atapi.com/hiwtab.htm the partition tables implement a
concept for which the partitions > 4 are best thought of as similar to
the primary extended partition (eg hda1): each starts with a special
sector having a partition table (and usually spare sectors on the rest
of that track) where the table has an entry for at most one logical
partition and at most one other nested extended partition.  So each
one is nested within all of the others before it.

But apparently the fdisk designers chose to present a different
picture of the situation.

Since fdisk gives "1" as the first sector of hda5, I suppose that
those partition first-sector numbers are actually for each partition's
table sector and not it's boot sector, which would typically be one
track further on.  But that would seem to make fdisk's fiction rather
a lie, since one normally thinks of the start of the partition as its
boot sector.  Hmmm.