System Administration Guide, Volume 1

Repairing a Defective Sector

If a disk on your system has a defective sector, you can repair it by using the instructions in the following procedures. You might become aware of defective sectors when you:

How to Identify a Defective Sector by Using Surface Analysis

  1. Become superuser.

  2. Unmount the file system in the slice that contains the defective sector.

    See mount(1M) for more information.

    # umount /dev/dsk/device-name
  3. Enter the format utility by typing format.

    # format
  4. Select the affected disk.

    Specify disk (enter its number):1
    selecting c0t2d0:
    [disk formatted]
    Warning: Current Disk has mounted partitions.
  5. Enter the analyze menu by typing analyze at the format> prompt.

    format> analyze
  6. Set up the analysis parameters by typing setup at the analyze> prompt. Use the parameters shown here:

    analyze> setup
    Analyze entire disk [yes]? n
    Enter starting block number [0, 0/0/0]: 12330
    Enter ending block number [2052287, 2035/13/71]: 12360
    Loop continuously [no]? y
    Repair defective blocks [yes]? n
    Stop after first error [no]? n
    Use random bit patterns [no]? n
    Enter number of blocks per transfer [126, 0/1/54]: 1
    Verify media after formatting [yes]? y
    Enable extended messages [no]? n
    Restore defect list [yes]? y
    Create defect label [yes]? y
  7. Use the read command to find the defect.

    analyze> read
    Ready to analyze (won't harm SunOS). This takes a long time,
    but is interruptible with Control-C. Continue? y
            pass 0
            pass 1
    Block 12354  (18/4/18), Corrected media error (hard data ecc)
    Total of 1 defective blocks repaired.

How to Repair a Defective Sector

  1. Become superuser.

  2. Enter the format utility and select the disk that contains the defective sector.

    # format
    Searching for disks...done
      0. c0t2d0 <SUN1.05 cyl 2036 alt 2 hd 14 sec 72>
      1. c0t3d0 <SUN1.05 cyl 2036 alt 2 hd 14 sec 72>
    Specify disk (enter its number): 1
    selecting c0t3d0
    [disk formatted]
  3. Enter the repair command at the format> prompt.

    format> repair
  4. Enter the defective block number.

    Enter absolute block number of defect: 12354
       Ready to repair defect, continue? y
       Repairing block 12354 (18/4/18)...ok.

    If you are unsure of the format used to identify the defective sector, see "How to Identify a Defective Sector by Using Surface Analysis" for more information.