AHDILABEL(8)         NetBSD/atari System Manager's Manual         AHDILABEL(8)

NAME
     ahdilabel -- modify AHDI partitions

SYNOPSIS
     ahdilabel disk

DESCRIPTION
     ahdilabel allows you to modify the AHDI partition table on a disk parti-
     tioned with AHDI or an AHDI compatible formatter.  The AHDI partition
     format is usually only present on disks shared between NetBSD and some
     other OS. The partition identifiers are used by NetBSD as a guideline to
     emulate a disklabel on such a disk.

     ahdilabel supports the following options:

     disk  The name of the disk you want to edit.  ahdilabel will first try to
           open a disk of this name.  If this cannot be opened, it will
           attempt to open r<disk>c.  Finally, if this also cannot be opened,
           it will attempt to open /dev/r<disk>c.

     ahdilabel will display information about the number of sectors, tracks
     and sectors on the disk, as well as the current AHDI partition informa-
     tion.  It will then prompt for input.  The input choices are:

     a-p  Modify a partition.  You will be prompted for a partition id, root,
          start and size.  NetBSD recognises the following partition id's:

          NBD         Partition is reserved for NetBSD.  This can be either a
                      root or an user partition. The first NBD partition on a
                      disk will be mapped to NetBSD partition letter a.  The
                      following NBD partitions will be mapped from letter d
                      up.  The filesystem type is ffs by default.
          SWP         The first SWP partition is mapped to partition b.
          GEM or BGM  These partitions are mapped from d up. The filesystem
                      type is msdos.

          The root, start and size parameters can be entered using sector,
          cylinder/track/sector or megabyte notations.  Whole numbers of
          cylinders can be entered using the shorthand <cylinder>/.  Likewise,
          whole numbers of tracks can be entered using the shorthand <cylin-
          der>/<track>/.  Megabytes are entered using the suffix M.

          The following can also be used to enter partition parameters:

          -N (root)   Position the root sector for this partition immediately
                      after partition N.
          -N (start)  Make this partition start after partition N (leaving a
                      gap of 1 sector for a root sector, if necessary).
          -N (size)   Make this partition end immediately before partition N.
          -1 (size)   Make this partition extend to the end of the disk.

          The sector holding the primary AHDI partition table only has space
          for four partitions.  Thus, if a disk has more than four partitions,
          the extra partition information is held in auxiliary root sectors.
          There is one auxiliary root for each additional partition (and also
          for the fourth partition, if the disk has more than four parti-
          tions).

     r    Recalculate the root sectors.  This will automatically assign auxil-
          iary root sectors if the disk has more than 4 partitions.  The aux-
          iliary root sectors will be positioned in a default location preced-
          ing the relevant partition.

     s    Show the current partition information.

     u    Toggle the unit display between sector and cylinder/track/sector
          notation.

     w    Write the AHDI partition table to the disk.

     z    Options for zero'ing the boot sector and bad sector lists.  The
          default is to preserve them both.

     q    Quit

EXAMPLES
           ahdilabel sd0
     Edit the AHDI label for disk sd0.

SEE ALSO
     bootpref(8), disklabel(8), installboot(8)

HISTORY
     The ahdilabel command first appeared in NetBSD 1.5.

BUGS
     The changes made to the AHDI partitions will become active on the next
     first open of the disk. You are advised to use ahdilabel only on a disk
     without any mounted or otherwise active partitions. This is not enforced
     by ahdilabel.

     Because of way NetBSD interprets AHDI partition tables to create the
     NetBSD disklabel, the NetBSD partition ordering may change if partitions
     labelled NBD are created or removed.

     Creating an AHDI partition table on a disk that previously did not have
     one will almost certainly overwrite any existing partition information
     and/or data on that disk.  This is especially the case if auxiliary root
     sectors are needed for the AHDI partition table.

     As soon as a disk contains at least one NBD partition, you are allowed to
     write NetBSD disklabels and install bootstraps.

NetBSD 5.0_STABLE                July 29, 2000               NetBSD 5.0_STABLE
