NAME
part - partition table editor
SYNOPSIS
part [device] ...
DESCRIPTION
Part is a screen oriented partition table editor.
While editing you will see six lines of numbers, the first
line shows the device name and its geometry (number of
cylinders, heads and sectors), the second shows the start
and end of the drive or partition you are working on, the
last four lines show the different partitions or subparti-
tions. All numbers except those on the second line can be
edited. Question marks are showed instead of numbers if the
partition table is not loaded yet. You have to select a
device and type 'r'.
Editing is a simple matter of moving around with the arrow
keys and changing the values with + and - (or PgUp and
PgDn), or by typing the desired value. The '?' key will
give a small list of commands, the '!' key gives advice on
how to make a new entry.
The spacebar toggles between showing the size of the parti-
tion and the last sector on the partition. Useful to check
if a partition is adjacent to the next.
The 'm' key is "magical", it lets you cycle through a set of
interesting values for the base or size of a partition.
These values are: Aligned to a cylinder, taped to other par-
titions (inside or outside), or filling out holes. Use this
key!
MINIX 3 subpartition tables or extended partitions may be
edited after hitting the '>' key. The number of this parti-
tion will be shown after the device name on the second row,
e.g. /dev/hd0:2. MINIX 3 subpartition tables are shown as
is, but extended partition bases are translated to absolute
offsets on the screen to hide the gory details of their
implementation from the innocent user. (Hit 'p' if you
dare.) The '<' key will bring you back to the enclosing
partition table.
With arguments, part will use the given devices or files.
Without arguments, part will use all interesting block dev-
ices in /dev sorted by device number and starting with
/dev/hd0.
Values that are out of range, overlapping, or otherwise
strange are shown in reverse video. Values that may
possibly be a problem for operating systems other then MINIX
3 are shown in bold characters.
The name of the device is highlighted when it has not been
read yet.
Head or sector numbers are highlighted if the partition does
not start or end at a cylinder boundary.
The base and/or size field is highlighted if they fall out-
side the device, if they are inside some other partition, if
the base equals the device's base (no room for the boot sec-
tor), or if the size is zero.
Part complies with the good old UNIX tradition of trusting
the user. It will write any table, no matter how bad. You
have been warned.
By the way, as far as MINIX 3 is concerned there is abso-
lutely no reason to make partitions start precisely on a
cylinder or track nor does it have to be an exact number of
cylinders long. MINIX 3 only looks at the base and size of
a partition, the geometry of the drive doesn't have to be
correct. Other Operating systems can be very picky about
partitions that are not aligned. Some partition editors may
refuse to edit a table, others may even make a mess of the
table. The only exception is the first partition, it tradi-
tionally starts on the first track, not the first cylinder.
All editors must understand this. (Subpartition tables are
MINIX 3 specific, so there is no reason at all for any
alignment.)
Extended Partitions
Extended partitions are a mess that is only made slightly
better by part by translating the base offsets to absolute
numbers. It is better to use DOS fdisk to create them, but
if you insist on using part then this is what they should
look like:
The extended partition entry in the primary partition
table must cover the whole logical partition space
within it.
The area thus created is split in segments, each seg-
ment contains a partition table in sector 0 and one
(just one) logical partition.
The first entry of a segment's partition table
describes this logical partition: it's partition ID,
base and size.
The second entry is an extended partition that
describes base and size of the next segment (partition
table and logical partition). The last segment's par-
tition table is empty, or contains one logical parti-
tion.
SEE ALSO
mkfs(1), fd(4), hd(4).
BUGS
You can have a table read, messed up, and written in no
time, be careful.
You can't type head or sector numbers directly.
Sectors are counted from 0 for consistency, but the parti-
tion table counts from 1 like DOS addresses them. Most
confusing.
You can't write a backup copy to a file, that's what dd(1)
with count=1 is for.
AUTHOR
Kees J. Bot (kjb@cs.vu.nl)