DVHTOOL(1M) DVHTOOL(1M) NAME dvhtool - modify and obtain disk volume header information SYNOPSIS /sbin/dvhtool [-b [ list ] [bootfile [rootpart [swappart]]]] [-v [creat unix_file dvh_file] [add unix_file dvh_file] [delete dvh_file] [get dvh_file unix_file] [list]] [header_filename] DESCRIPTION Dvhtool allows modification of the disk volume header information, 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 files kept in the volume header area of the disk for standalone use. The partition table describes the logical device partitions. The device parameters describe the specifics of a particular disk drive. Note that it is necessary to be superuser in order to use dvhtool. Invoked with no arguments (or just a volume header name), dvhtool allows the user to interactively examine and modify the disk volume header on the root drive. The read command prompts for the name of the device file for the volume header to be worked on. This may be /dev/rvh for the header of the root disk, or the header name of another disk in the /dev/rdsk directory. See vh(7m). It then 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. Note: use of dvhtool for changing partitions and parameters is not recommended. Parameters and partitions should be manipulated with fx(1m). Invoked with arguments, dvhtool reads the volume header, performs the specified operations, and then writes the volume header. If no header_filename is specified on the command line, /dev/rvh is used. The following describes dvhtool's command line arguments. The -b flag allows you to set the current bootfile, root, and swap partitions. The list option displays their current settings. The -v flag provides five options for modifying and listing the contents of the volume directory information in the disk volume header: create, add, delete, get, and list. 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. Page 1 DVHTOOL(1M) DVHTOOL(1M) 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 will not overwrite an existing entry. The delete option removes the entry named dvh_file, if it exists, from the volume directory. The get option copies the requested file from the volume header to the file system. The list option lists the current volume directory contents. SEE ALSO vh(7m) fx(1m) NOTE Several Mbytes of disk space may be required in the /tmp directory when creating or adding files if the free space in the volume header is fragmented. This also makes dvhtool run much slower, since all files must then be copied to /tmp, and then back to the volume header. Page 2