Re: Partition confusion

[zelinsky@us.net (David S. Zelinsky)]

Kent West <westk@heir.acu.edu> writes:

> So I can have three primary partitions, and then the fourth and final "slot"
> functions as a pointer to another table? (Or two and two, or four primaries,
> or 1 and 3, etc?) Is the extended partition table limited to 4 partitions as
> well, so that if I wanted 8 partitions I could have 3 primary, 1 extended
> pointing to 3 others (3+3=6), and the fourth extended "slot" pointing to a
> third table (second extended) holding the final ((3+3-6)+1=7)?

>From the `Partition' mini-HOWTO (file:/usr/doc/HOWTO/Partition.gz):

  For compatibility reasons, the space occupied by all logical
  partitions had to be accounted for. If you are using logical
  partitions, one primary partition entry is marked as "extended
  partition" and its starting and ending block mark the area occupied by
  your logical partitions. This implies that the space assigned to all
  logical partitions has to be contiguous.  There can be only one
  extended partition: no fdisk program will create more than one
  extended partition.

  Linux cannot handle more than a limited number of partitions per
  drive. So in Linux you have 4 primary partitions (3 of them useable,
  if you are using logical partitions) and at most 15 partitions
  altogether on an SCSI disk (63 altogether on an IDE disk).

So to get 8 partitions, you could have 3 primaries, and one extended holding 5
logical partitions.  Or 2 primary and 6 logical partitions.  Or 1+7, or 0+8.

--
David Zelinsky
dsz@alumni.caltech.edu