From: almesber@nessie.cs.id.ethz.ch (Werner Almesberger) Subject: Partition types (was Re: name confusion in fdisk, etc...) Date: Sun, 30 May 1993 13:49:57 GMT
In article <SCT.93May24193910@ascrib.dcs.ed.ac.uk> sct@dcs.ed.ac.uk (Stephen Tweedie) writes:
> You can put an extended filesystem onto an extended partition or onto a
> primary partition.
Some confusion probably also exists because the distinction between
extended and logical partitions is often neglected ;-)
Let me summarize this bit ... There are three fundamentally different types
of PC partitions:
PRIMARY partitions. Each hard disk has up to four of them. Their locations
and sizes are stored in the partition table of the master boot record (MBR).
Primary partitions are numbered 1-4 (*) on Linux.
(*) E.g. /dev/hda1, /dev/sda3, /dev/hdb2, ...
EXTENDED partitions. They are special primary partitions. Typically, a hard
disk can have zero or one extended partitions. Extended partitions don't
contain actual data (swap space, file systems, etc.). One exception: they
can be used to store a boot sector, like LILO can do it, because the first
sector of an extended partition resembles the MBR. Because extended
partitions are just a special type of primary partitions, they are also
numbered 1-4 on Linux.
LOGICAL partitions. They are _inside_ an extended partition. Unlike primary
partitions, they are not described in a single table, but form a linked
list. (I.e. their number is not limited by design.) Logical partitions are
numbered 5, 6, etc. on Linux.
- Werner
-- _________________________________________________________________________ / Werner Almesberger, ETH Zuerich, CH almesber@nessie.cs.id.ethz.ch / /_IFW_A44__Tel._+41_1_254_7213__________________almesber@bernina.ethz.ch_/