edvtoc(1M)

edvtoc -- VTOC (Volume Table of Contents) editing utility

Synopsis

edvtoc -f vtoc-file raw-device
edvtoc -p raw-device
edvtoc -s "stamp" raw-device

Description

The first form of the edvtoc command allows you to edit the contents of the Volume Table Of Contents (VTOC). The second form lets you update the disk parameters stored in your VTOC so that they reflect the ones currently in use on your system.

Options

-f vtoc-file: Specifies the path location of the updated (condensed format) VTOC file to be written to disk. The format of the file is slice number, slice tag value, slice flag value, slice start sector, slice size (in sectors). A copy of this file can be obtained for modification by using the -f option of the prtvtoc(1M) command.
-p: Specifies that the disk parameters stored in the VTOC on the specified disk should be updated. These parameters include the number of heads and the numbers of sectors per track that are defined for the specified disk device.
-s stamp: Specifies the stamp value (an array of 12 characters) to write to the on-disk PDINFO (Physical Disk Information). The notation for default stamp is a string of 12 blank characters. This option should only be used to resolve stamp collisions. The default value should be used to minimize the probability of a stamp collision.
raw-device: raw-device is the character special device for the disk drive to be accessed. It must be the slice 0 device to represent the entire device (for example, /dev/rdsk/c0b0t0d0s0).

Files

/dev/rdsk/cCbBtTdDs0

Usage

The required procedure for editing the VTOC includes the following steps:

Ensure that the disk (other than the root disk) is not open.
Run prtvtoc(1M) with the -f option.
Edit the file created by prtvtoc to reflect the needed changes to the VTOC.
Run edvtoc on the edited file.
For the root disk, reboot the system, so the disk driver can read the new VTOC. The changes to the VTOC on the root disk will not take place until you perform the reboot.

edvtoc provides three functions:

reading/interpreting vtoc-file
limited validity checking of the new VTOC
writing the VTOC to the disk if the user requests it

When editing the VTOC, the following entries are the valid slice tags and slice permission flags:

   /* Slice tags */
   
   #define V_BOOT		0x01	/* Boot slice */
   #define V_ROOT		0x02	/* Root filesystem */
   #define V_SWAP		0x03	/* Swap filesystem */
   #define V_USR		0x04	/* User filesystem */
   #define V_BACKUP	0x05	/* full disk */
   #define V_ALTS		0x06	/* alternate sector space */
   #define V_OTHER		0x07	/* non-unix space */
   #define V_ALTTRK	0x08	/* alternate track space */
   #define V_STAND		0x09	/* Stand slice */
   #define V_VAR		0x0a	/* Var slice */
   #define V_HOME		0x0b	/* Home slice */
   #define V_DUMP		0x0c	/* dump slice */
   #define V_ALTSCTR	0x0d	/* Alternate sector/track */
   #define V_MANAGED1	0x0e	/* Volume management public slice */
   #define V_MANAGED2	0x0f	/* Volume management private slice */
   

   

   /* Slice permission flags */
   

   #define V_UNMNT		0x01	/* Unmountable partition */
   #define V_RONLY		0x10	/* Read only */
   #define V_VALID		0x200	/* Partition is valid to use */

The start and size value are in absolute sector numbers where the first sector on the drive is 0 (which is reserved for the partition table). Slices should start and end on a cylinder boundary if possible. The head, cylinder and sectors/track information provided by prtvtoc -p assists in the calculations. Slices should not overlap (slice 0 is the exception, it describes the entire UNIX partition).

The -p option causes edvtoc to update the disk parameters recorded on the specified disk device with the disk parameters that were detected when the disk was recognized. Normally, these parameters match but, either by moving the disk to a different controller or by changing the size of a logical disk, the parameters recorded on the disk may be incorrect. If you are trying to mount filesystems that are on an existing disk and you can not because the system believes that the disk parameters are no longer compatible, you may use this option to change the disk parameters so that the filesystems are mountable.

References

disk(7), prtvtoc(1M), sd01(7), vtoc(7)