System Administration Guide: Basic Administration

Creating and Examining a Disk Label

The labeling of a disk is usually done during system installation or when you are creating new disk slices. You might need to relabel a disk if the disk label becomes corrupted (for example, from a power failure).

The format utility attempts to automatically configure any unlabeled SCSI disk. If the format utility is able to automatically configure an unlabeled disk, it displays a message like the following:


	c1t0d0:configured with capacity of 404.65MB

Tip –

For information on labeling multiple disks with the same disk label, see Label Multiple Disks by Using the prtvtoc and fmthard Commands.


How to Label a Disk

  1. Become superuser or assume an equivalent role.

  2. Invoke the format utility.


    # format
    
  3. Type the number of the disk that you want to label from the list displayed on your screen.


    Specify disk (enter its number):1
    
  4. Select one of the following.

    1. If the disk is unlabeled and was successfully configured, go to step 5 to label the disk.

      The format utility will ask if you want to label the disk.

    2. If the disk is labeled and you want to change the disk type, or if the format utility was not able to automatically configure the disk, follow steps 6-7 to set the disk type and label the disk.

  5. Label the disk by typing y at the Label it now? prompt.


    Disk not labeled. Label it now? y
    

    The disk is now labeled. Go to step 10 to exit the format utility.

  6. Enter type at the format> prompt.


    format> type
    

    The Available Drive Types menu is displayed.

  7. Select a disk type from the list of possible disk types.


    Specify disk type (enter its number)[12]: 12
    

    Or, select 0 to automatically configure a SCSI-2 disk. For more information, see How to Automatically Configure a SCSI Drive.

  8. Label the disk. If the disk is not labeled, the following message is displayed.


    Disk not labeled. Label it now? y
    

    Otherwise, you are prompted with this message:


    Ready to label disk, continue? y
    
  9. Verify the disk label.


    format> verify 
    
  10. Exit the format utility.


    partition> q
    format> q
    #

Example—Labeling a Disk

The following example shows how to automatically configure and label a 1.05-Gbyte disk.


# format
	c1t0d0: configured with capacity of 1002.09MB
 
AVAILABLE DISK SELECTIONS:
	  0. c0t3d0 <SUN1.05 cyl 2036 alt 2 hd 14 sec 72>
     /iommu@f,e0000000/sbus@f,e0001000/espdma@f,400000/esp@f,800000/sd@1,0
	  1. c1t0d0 <SUN1.05 cyl 2036 alt 2 hd 14 sec 72>
     /iommu@f,e0000000/sbus@f,e0001000/espdma@f,400000/esp@f,800000/sd@1,0
Specify disk (enter its number): 1
Disk not labeled.  Label it now?  yes
format> verify
#

How to Examine a Disk Label

Examine disk label information by using the prtvtoc command. For a detailed description of the disk label and the information that is displayed by the prtvtoc command, see Chapter 31, Managing Disks (Overview).

  1. Become superuser or assume an equivalent role.

  2. Display the disk label information.


    # prtvtoc /dev/rdsk/device-name
    

    device-name is the raw disk device you want to examine.

Example—Examining a Disk Label

The following example shows the disk label information for disk /dev/rdsk/c0t1d0s0.


# prtvtoc /dev/rdsk/c0t1d0s0
* /dev/rdsk/c0t1d0s0 partition map
*
* Dimensions:
*     512 bytes/sector
*      72 sectors/track
*      14 tracks/cylinder
*    1008 sectors/cylinder
*    2038 cylinders
*    2036 accessible cylinders
*
* Flags:
*   1: unmountable
*  10: read-only
*
*                          First     Sector    Last
* Partition  Tag  Flags    Sector     Count    Sector  Mount Directory
       0      2    00          0    303408    303407   /
       1      3    01     303408    225792    529199
       2      5    00          0   2052288   2052287
       6      4    00     529200   1523088   2052287   /usr
#