Hi,
I have a Hitachi HTS421212H9AT00 hard disk on my laptop. I recently ran the smartctl tool to test my hard disk from Ubuntu 8.04 after my windows failed to boot up.
The raw values extracted from an extended offline test result stated...

Current_Pending_Sector   : 1
Offline_Uncorrectable    : 0
Reallocated_Sector_Ct    : 0
Reallocated_Event_Count  : 4
The test log stated LBA 7333131 had failed the test.

Q1) When the offline uncorrectable count is 0 what does it state regarding the kind of damage the disk has sustained? I mean is it a permanent damage or something that can be repaired through a write to the block?

After learning that Hitachi provides a utility called the Drive Fitness Test(DFT) which could test and repair bad blocks I gave it shot.
Now after running the tool (where it found bad blocks and made repairs) I ran smartctl extended offline test again and the result are...
Current_Pending_Sector   : 0
Offline_Uncorrectable    : 0
Reallocated_Sector_Ct    : 0
Reallocated_Event_Count  : 4

Q2) Shouldn't the count of offline uncorrectable blocks be 1 (or more) and the reallocated sector count also be atleast 1?

Q3) Note that the reallocated event's count in raw value has not increased after running the DFT tool. Can that be interpreted as no blocks had to be reallocated to repair the problem?

Q4) Just to be reassured, does this result mean that my hard disk had sustained no permanent damage and whatever bad blocks it had were fully repaired by the tool?


In case it helps I've pasted the full output of running "smartctl -a" after using the DFT tool below...

Thanks in advance.

smartctl -a output:
smartctl version 5.37 [i686-pc-linux-gnu] Copyright (C) 2002-6 Bruce Allen
Home page is http://smartmontools.sourceforge.net/

=== START OF INFORMATION SECTION ===
Device Model:     HTS421212H9AT00
Serial Number:    HKA410ALGBS0VB
Firmware Version: HA4OA70S
User Capacity:    120,034,123,776 bytes
Device is:        Not in smartctl database [for details use: -P showall]
ATA Version is:   7
ATA Standard is:  ATA/ATAPI-7 T13 1532D revision 1
Local Time is:    Mon May 26 21:12:59 2008 CEST
SMART support is: Available - device has SMART capability.
SMART support is: Enabled

=== START OF READ SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED

General SMART Values:
Offline data collection status:  (0x02)    Offline data collection activity
                    was completed without error.
                    Auto Offline Data Collection: Disabled.
Self-test execution status:      (   0)    The previous self-test routine completed
                    without error or no self-test has ever
                    been run.
Total time to complete Offline
data collection:          ( 645) seconds.
Offline data collection
capabilities:              (0x5b) SMART execute Offline immediate.
                    Auto Offline data collection on/off support.
                    Suspend Offline collection upon new
                    command.
                    Offline surface scan supported.
                    Self-test supported.
                    No Conveyance Self-test supported.
                    Selective Self-test supported.
SMART capabilities:            (0x0003)    Saves SMART data before entering
                    power-saving mode.
                    Supports SMART auto save timer.
Error logging capability:        (0x01)    Error logging supported.
                    General Purpose Logging supported.
Short self-test routine
recommended polling time:      (   2) minutes.
Extended self-test routine
recommended polling time:      (  89) minutes.

SMART Attributes Data Structure revision number: 16
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE
  1 Raw_Read_Error_Rate     0x000b   100   100   062    Pre-fail  Always       -       0
  2 Throughput_Performance  0x0005   107   107   040    Pre-fail  Offline      -       5740
  3 Spin_Up_Time            0x0007   118   118   033    Pre-fail  Always       -       2
  4 Start_Stop_Count        0x0012   099   099   000    Old_age   Always       -       2845
  5 Reallocated_Sector_Ct   0x0033   100   100   005    Pre-fail  Always       -       0
  7 Seek_Error_Rate         0x000b   100   100   067    Pre-fail  Always       -       0
  8 Seek_Time_Performance   0x0005   118   118   040    Pre-fail  Offline      -       41
  9 Power_On_Hours          0x0012   091   091   000    Old_age   Always       -       4323
 10 Spin_Retry_Count        0x0013   100   100   060    Pre-fail  Always       -       0
 12 Power_Cycle_Count       0x0032   099   099   000    Old_age   Always       -       1618
191 G-Sense_Error_Rate      0x000a   100   100   000    Old_age   Always       -       0
192 Power-Off_Retract_Count 0x0032   100   100   000    Old_age   Always       -       95
193 Load_Cycle_Count        0x0012   083   083   000    Old_age   Always       -       173263
194 Temperature_Celsius     0x0002   110   110   000    Old_age   Always       -       50 (Lifetime Min/Max 12/60)
196 Reallocated_Event_Count 0x0032   100   100   000    Old_age   Always       -       4
197 Current_Pending_Sector  0x0022   100   100   000    Old_age   Always       -       0
198 Offline_Uncorrectable   0x0008   100   100   000    Old_age   Offline      -       0
199 UDMA_CRC_Error_Count    0x000a   200   200   000    Old_age   Always       -       0

SMART Error Log Version: 1
ATA Error Count: 29 (device log contains only the most recent five errors)
    CR = Command Register [HEX]
    FR = Features Register [HEX]
    SC = Sector Count Register [HEX]
    SN = Sector Number Register [HEX]
    CL = Cylinder Low Register [HEX]
    CH = Cylinder High Register [HEX]
    DH = Device/Head Register [HEX]
    DC = Device Command Register [HEX]
    ER = Error register [HEX]
    ST = Status register [HEX]
Powered_Up_Time is measured from power on, and printed as
DDd+hh:mm:SS.sss where DD=days, hh=hours, mm=minutes,
SS=sec, and sss=millisec. It "wraps" after 49.710 days.

Error 29 occurred at disk power-on lifetime: 4322 hours (180 days + 2 hours)
  When the command that caused the error occurred, the device was active or idle.

  After command completion occurred, registers were:
  ER ST SC SN CL CH DH
  -- -- -- -- -- -- --
  10 51 00 09 4f c2 a0  Error: IDNF

  Commands leading to the command that caused the error were:
  CR FR SC SN CL CH DH DC   Powered_Up_Time  Command/Feature_Name
  -- -- -- -- -- -- -- --  ----------------  --------------------
  b0 d6 01 09 4f c2 a0 00      07:48:20.900  SMART WRITE LOG
  b0 d5 01 09 4f c2 a0 00      07:48:20.700  SMART READ LOG
  b0 d1 01 01 4f c2 a0 00      07:48:20.700  SMART READ ATTRIBUTE THRESHOLDS [OBS-4]
  b0 d0 01 00 4f c2 a0 00      07:48:20.700  SMART READ DATA
  b0 da 00 00 4f c2 a0 00      07:48:20.700  SMART RETURN STATUS

Error 28 occurred at disk power-on lifetime: 4321 hours (180 days + 1 hours)
  When the command that caused the error occurred, the device was active or idle.

  After command completion occurred, registers were:
  ER ST SC SN CL CH DH
  -- -- -- -- -- -- --
  40 59 01 0b e5 6f e0  Error: UNC at LBA = 0x006fe50b = 7333131

  Commands leading to the command that caused the error were:
  CR FR SC SN CL CH DH DC   Powered_Up_Time  Command/Feature_Name
  -- -- -- -- -- -- -- --  ----------------  --------------------
  24 00 01 0b e5 6f e0 02      06:14:18.800  READ SECTOR(S) EXT
  24 00 01 0a e5 6f e0 02      06:14:18.800  READ SECTOR(S) EXT
  24 00 01 09 e5 6f e0 02      06:14:18.800  READ SECTOR(S) EXT
  24 00 01 08 e5 6f e0 02      06:14:18.800  READ SECTOR(S) EXT
  24 00 01 07 e5 6f e0 02      06:14:18.800  READ SECTOR(S) EXT

Error 27 occurred at disk power-on lifetime: 4321 hours (180 days + 1 hours)
  When the command that caused the error occurred, the device was active or idle.

  After command completion occurred, registers were:
  ER ST SC SN CL CH DH
  -- -- -- -- -- -- --
  40 51 f5 0b e5 6f e0  Error: UNC at LBA = 0x006fe50b = 7333131

  Commands leading to the command that caused the error were:
  CR FR SC SN CL CH DH DC   Powered_Up_Time  Command/Feature_Name
  -- -- -- -- -- -- -- --  ----------------  --------------------
  42 00 00 00 00 6f e0 02      06:13:48.500  READ VERIFY SECTOR(S) EXT
  42 00 00 00 00 6e e0 02      06:13:47.600  READ VERIFY SECTOR(S) EXT
  42 00 00 00 00 6d e0 02      06:13:46.600  READ VERIFY SECTOR(S) EXT
  42 00 00 00 00 6c e0 02      06:13:45.700  READ VERIFY SECTOR(S) EXT
  42 00 00 00 00 6b e0 02      06:13:44.700  READ VERIFY SECTOR(S) EXT

Error 26 occurred at disk power-on lifetime: 4315 hours (179 days + 19 hours)
  When the command that caused the error occurred, the device was active or idle.

  After command completion occurred, registers were:
  ER ST SC SN CL CH DH
  -- -- -- -- -- -- --
  40 59 01 0b e5 6f e0  Error: UNC at LBA = 0x006fe50b = 7333131

  Commands leading to the command that caused the error were:
  CR FR SC SN CL CH DH DC   Powered_Up_Time  Command/Feature_Name
  -- -- -- -- -- -- -- --  ----------------  --------------------
  24 00 01 0b e5 6f e0 02      00:23:00.500  READ SECTOR(S) EXT
  24 00 01 0a e5 6f e0 02      00:23:00.500  READ SECTOR(S) EXT
  24 00 01 09 e5 6f e0 02      00:23:00.500  READ SECTOR(S) EXT
  24 00 01 08 e5 6f e0 02      00:23:00.500  READ SECTOR(S) EXT
  24 00 01 07 e5 6f e0 02      00:23:00.500  READ SECTOR(S) EXT

Error 25 occurred at disk power-on lifetime: 4315 hours (179 days + 19 hours)
  When the command that caused the error occurred, the device was active or idle.

  After command completion occurred, registers were:
  ER ST SC SN CL CH DH
  -- -- -- -- -- -- --
  40 51 f5 0b e5 6f e0  Error: UNC at LBA = 0x006fe50b = 7333131

  Commands leading to the command that caused the error were:
  CR FR SC SN CL CH DH DC   Powered_Up_Time  Command/Feature_Name
  -- -- -- -- -- -- -- --  ----------------  --------------------
  42 00 00 00 00 6f e0 02      00:22:29.700  READ VERIFY SECTOR(S) EXT
  42 00 00 00 00 6e e0 02      00:22:28.800  READ VERIFY SECTOR(S) EXT
  42 00 00 00 00 6d e0 02      00:22:27.800  READ VERIFY SECTOR(S) EXT
  42 00 00 00 00 6c e0 02      00:22:26.900  READ VERIFY SECTOR(S) EXT
  42 00 00 00 00 6b e0 02      00:22:25.900  READ VERIFY SECTOR(S) EXT

SMART Self-test log structure revision number 1
Num  Test_Description    Status                  Remaining  LifeTime(hours)  LBA_of_first_error
# 1  Selective offline   Completed without error       00%      4322         -
# 2  Short offline       Completed without error       00%      4316         -
# 3  Extended offline    Completed: read failure       90%      4310         7333131
# 4  Extended offline    Completed: read failure       90%      4309         7333131
# 5  Short offline       Completed without error       00%      4308         -
# 6  Extended offline    Completed: read failure       90%      4306         7333131
# 7  Short offline       Completed without error       00%      4306         -

Warning! SMART Selective Self-Test Log Structure error: invalid SMART checksum.
SMART Selective self-test log data structure revision number 1
 SPAN  MIN_LBA  MAX_LBA  CURRENT_TEST_STATUS
    1        0        0  Not_testing
    2        0        0  Not_testing
    3        0        0  Not_testing
    4        0        0  Not_testing
    5        0        0  Not_testing
Selective self-test flags (0x0):
  After scanning selected spans, do NOT read-scan remainder of disk.
If Selective self-test is pending on power-up, resume after 0 minute delay.