NAME

dvhtool − modify disk volume header information

SYNOPSIS

/etc/dvhtool [ modify part nblks 1st_blk type] [list]
[-v [add unix_file dvh_file][creat unix_file dvh_file]
[delete dvh_file][list]]
[-d [modify name value][list]]
[dvh_file -m partition_no filesys_type]

DESCRIPTION

dvhtool allows modification of the disk volume header information, where the disk volume header is a block located at the beginning of all disk media.  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 parameters describe the specifics of a particular disk drive. 

Invoked with no arguments, dvhtool allows the user to examine and modify the disk volume header interactively.  The read command reads the volume header from the specified device.  The vd, pt, and dp commands 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. 

Invoked with arguments, dvhtool reads the volume header, performs the specified operations, and then writes the volume header.  The following paragraphs describe dvhtool’s command line arguments. 

The -v flag provides four options for modifying the volume directory information in the disk volume header.  The creat option allows creation of a volume directory with the name dvh_name 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 directory entry with the name dvh_file and the contents of unix_file.  Unlike the creat option, the add options do not overwrite an existing entry.  The delete option removes the entry named dvh_file, if it exists, from the volume directory.  The list option lists the current volume directory contents. 

The -m flag allows dvhtool to invoke mkfs and make a file system of the type filesys_type (either 4K for System V or AFFS for Ardent Fast File System) on partition partition_no on the drive named by dvh_file.  Mkfs will be invoked with default parameters which covers the entire partition. 

The -d flag provides two options for modifying the device parameter information in the disk volume header.  The modify options sets the name device parameter to the specified valuef1.  The list option lists the current device parameters. 

SEE ALSO

mkfs(1M)

September 02, 1992