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)