

PART(8)                   Minix Programmer's Manual                    PART(8)


NAME
     part - partition table editor

SYNOPSIS
     part [device] ...

DESCRIPTION
     Part is a screen oriented partition table editor.  It does the  same  job
     as fdisk(8), but is much easier to use and a lot less restrictive.

     On the screen you will see six lines of  numbers,  the  first  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  third  to  sixth line show the different partitions or
     subpartitions.  All numbers but those on the second line can be edited.

     Editing is a simple matter of moving  around  with  the  arrow  keys  and
     changing  the values with + and - (or PgUp and PgDn), or by simply typing
     the desired value.  The '?' key will give a small list of commands.

     The spacebar toggles between showing the size of the  partition  and  the
     last  sector  on  the  partition.   It  also modifies the way changes are
     interpreted.  While "Size" is shown, part will not change the size of the
     partition,  while  "Last"  is  shown, you can modify begin and end of the
     partition separately.

     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 partitions (inside or outside), or filling out
     holes.  Use this key !

     Minix subpartition tables or extended  partitions  may  be  edited  after
     hitting  the  '>'  key.  The number of this partition will be shown after
     the device name on the second row, e.g.  /dev/hd0:2.  Minix  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.  The '<' 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 devices 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 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  outside  the
     device,  if  they are inside some other partition, if the base equals the
     device's base (no room for the boot sector), or if the size is zero.



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PART(8)                   Minix Programmer's Manual                    PART(8)


     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 is concerned there is absolutely no reason to
     make  partitions  start precisely on a cylinder or track nor does it have
     to be exactly n cylinders long.  Minix 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  traditionally  starts  on  the first track, not the first
     cylinder.  All editors must understand this.

  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 segment 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 partition table is empty, or contains one logical
          partition.

SEE ALSO
     fd(4), hd(4), fdisk(8).

BUGS
     You can have a table read, messed up, and written in no time, be careful.

     You can't type head and sector numbers directly.

     Sectors are counted from 0, fdisk 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)









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