disksecn(1M)                                                   disksecn(1M)
                               Series 800 Only



 NAME    [Toc]    [Back]
      disksecn - calculate default disk section sizes

 SYNOPSIS    [Toc]    [Back]
      disksecn [-p|-d] [-b block_size] [-n disk_name]

 DESCRIPTION    [Toc]    [Back]
      disksecn is used to calculate the disk section sizes based on the
      Berkeley disk partitioning method.

      disksecn recognizes the following options:

           -p             Produce tables suitable for inclusion in the
                          device driver.

           -d             Produce tables suitable for generating the disk
                          description file /etc/disktab.

           -b block_size  When generating the above tables, use a sector
                          size of block_size bytes, where block_size can be
                          256, 512, 1024, or 2048.  Defaults to DEV_BSIZE
                          (defined in <sys/param.h>) if not specified.

           -n disk_name   Specifies the disk name to be used in calculating
                          sector sizes; for example, hp7912 or hp7945.  If
                          an unknown disk name is specified, disksecn
                          prompts the user for the necessary disk
                          information.

      If neither -p nor -d table selection switches are specified a default
      table of the section sizes and range of cylinders used is output.

      Disk section sizes are based on the total amount of space on the disk
      as given in the table below (all values are supplied in units of 256-
      byte sectors).  If the disk is smaller than approximately 44 Mbytes,
      disksecn aborts and returns the message disk too small, calculate by
      hand.


           Section   44-56MB   57-106MB   107-332MB   333+MB
              0        97120      97120       97120    97120
              1        39064      39064      143808   194240
              3        39064      39064       78128   117192
              4       unused      48560      110096   429704
              6         7992       7992        7992     7992
             10       unused     unused      unused   516096

      NOTE:
      It is important to note the difference between the block size passed
      into disksecn via the -b switch argument and the sector size the user
      is asked to input when an unknown disk name is passed to disksecn via



 Hewlett-Packard Company            - 1 -   HP-UX 11i Version 2: August 2003






 disksecn(1M)                                                   disksecn(1M)
                               Series 800 Only



      the -n switch argument.

      The block size is the sector size that disksecn assumes the disk to
      have when it prints the requested tables.  All information printed in
      the tables is adjusted to reflect this assumed sector size (block
      size) passed in by the user.  The sector size requested by disksecn
      when an unknown disk name is passed does not necessarily have to be
      the same as the assumed sector size (block size) passed in by the -b
      switch argument.

      For example, a user wants to see the device driver tables for the disk
      named hp7945 with an assumed sector size (block size) of 256 bytes.
      The user has the following information about the hp7945 disk:

           Disk type = winchester
           Sector size = 512
           Number of sectors per track (512 byte sectors) = 16
           Number of tracks = 7
           Number of cylinders = 968
           Revolutions per minute = 3600

      The user invokes disksecn by typing the following command:

           disksecn -p -b 256 -n hp7945

      Assuming that hp7945 is an unknown disk name, disksecn prompts the
      user for the necessary disk information.  The user should input the
      information as shown above, reflecting a sector size of 512 bytes.
      All the information will be adjusted within disksecn to reflect the
      assumed sector size (block size) of 256 bytes, passed as the argument
      of the -b switch, before the requested device driver table is output.

      This adjustment also takes place when the disk name is known and an
      assumed sector size (block size) is passed in as the argument of the
      -b switch which is not DEV_BSIZE bytes, the assumed sector size (block
      size) used to create the etc/disktab file.

 RETURN VALUE    [Toc]    [Back]
      disksecn returns the following values:

           0    Successful completion.
           1    Usage error.
           2    User did not input parameters for an unknown disk.
           3    Disk too small or an invalid block size.

      disksecn aborts and prints an error message under the following
      conditions:

           +  disksecn was invoked without specifying a disk name.
           +  Requested both -p and -d switch.




 Hewlett-Packard Company            - 2 -   HP-UX 11i Version 2: August 2003






 disksecn(1M)                                                   disksecn(1M)
                               Series 800 Only



           +  Illegal block size requested.
           +  Unknown disk name was specified and user did not supply disk
              information.
           +  Disk's maximum storage space is less than approximately 44 MB.

 WARNINGS    [Toc]    [Back]
      Alternate names are not included in the output when the -d switch is
      used.

      Blanks are required in the command line between each of the switches
      when invoking disksecn.

      A blank is required between the -n switch and the disk name argument
      to that switch.  For example:

           disksecn -p -b 1024 -n hp9712

      disksecn does not save the block size used to generate the
      /etc/disktab disk description file.  The system assumes that the block
      size used was DEV_BSIZE when it reads the information stored in the
      etc/disktab file.

 AUTHOR    [Toc]    [Back]
      disksecn was developed by the University of California, Berkeley.

 FILES    [Toc]    [Back]
      /etc/disktab

 SEE ALSO    [Toc]    [Back]
      disktab(4).


 Hewlett-Packard Company            - 3 -   HP-UX 11i Version 2: August 2003