DVHTOOL(1M)         RISC/os Reference Manual          DVHTOOL(1M)



NAME
     dvhtool - modify disk volume header information

SYNOPSIS
     /etc/dvhtool [-f volume] [-v [add unix_file dvh_file] [creat
     unix_file dvh_file]
          [bootfile unix_file] [delete dvh_file] [list]]

DESCRIPTION
     dvhtool allows modification of the disk volume header infor-
     mation, a block located at the beginning of all disk media.
     This block is written out when the disk is formatted.  The
     disk volume header consists of three main parts:  the device
     parameters, the partition table, and the volume directory.
     The volume directory is used to locate such things as the
     boot block and the bad sector table.  The partition table
     describes the logical device partitions.  The device parame-
     ters describe the specifics of a particular disk drive.

     Invoked with no arguments, dvhtool allows the user to
     interactively examine and modify the disk volume header.  It
     prompts the user with the following line:

          Command? (read, vd, pt, dp, write, bootfile, or quit):

     The read command reads the volume header from the specified
     device, usually /dev/dsk/ipc0d0vh.  The vd (volume direc-
     tory), pt (partition table), and dp (device parameter) com-
     mands first list their respective portions of the volume
     header and then prompt for modifications.  The write command
     writes the possibly modified volume header to the device.
     The bootfile command prompts the user to change the bootfile
     name.

     Invoked with arguments, dvhtool reads the volume header,
     performs the specified operations, and then writes the
     volume header if it has been modified.  For instance, if
     only the -v list option is specified, the volume header
     isn't rewritten.  The following describes dvhtool's command
     line arguments.

     The -f flag allows a device to be specified. If this option
     is not used, the default device /dev/dsk/ipc0d0vh will be
     used.

     The -v flag provides five options for modifying the volume
     directory information in the disk volume header.  The creat
     option allows creation of a volume directory entry with the
     name dvh_file and the contents of unix_file. If an entry
     already exists with the name dvh_file, it is overwritten
     with the new contents.  The add option adds a volume direc-
     tory entry with the name dvh_file and the contents of



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DVHTOOL(1M)         RISC/os Reference Manual          DVHTOOL(1M)



     unix_file. It will not overwrite an existing entry.  The
     delete option removes the entry named dvh_file, if it
     exists, from the volume directory.  The bootfile option
     changes the bootfile name to file. The list option lists the
     current volume directory contents.

SEE ALSO
     auto(1prom), dkip(7).
     dvh(4) in the Programmer's Reference Manual.














































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