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For some reason, my pending sector count to be remapped is unbelievably high (2163 currently). I've seen it go up 20 in one week. But no sectors have been remapped. Dell's computer diagnostics utility reported no problems, smartctl -H returned PASSED, and I have yet to notice any problems with the hard drive.

So do I need to worry about such a high pending count?

Here are the results of smartctl -A:

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     0x000f   100   100   051    Pre-fail  Always       -       0
  3 Spin_Up_Time            0x0007   252   252   025    Pre-fail  Always       -       2062
  4 Start_Stop_Count        0x0032   097   097   000    Old_age   Always       -       36147
  5 Reallocated_Sector_Ct   0x0033   252   252   010    Pre-fail  Always       -       0
  9 Power_On_Hours          0x0032   095   095   000    Old_age   Always       -       3261
 12 Power_Cycle_Count       0x0032   098   098   000    Old_age   Always       -       2087
191 G-Sense_Error_Rate      0x0032   002   002   000    Old_age   Always       -       999999
192 Power-Off_Retract_Count 0x0032   100   100   000    Old_age   Always       -       47
194 Temperature_Celsius     0x0022   127   094   000    Old_age   Always       -       37 (Lifetime Min/Max 13/48)
196 Reallocated_Event_Count 0x0032   100   100   000    Old_age   Always       -       191990
197 Current_Pending_Sector  0x0012   100   100   000    Old_age   Always       -       2163
198 Offline_Uncorrectable   0x0030   100   100   000    Old_age   Offline      -       19080
199 UDMA_CRC_Error_Count    0x0036   252   252   000    Old_age   Always       -       0
200 Multi_Zone_Error_Rate   0x000a   252   252   000    Old_age   Always       -       0

Edit:

The disk is about 1 1/2 years old. Pending Sector Count was about 2000 when I started keeping an eye on it 2 weeks ago. I have never noticed any problems with the disk. If it makes any difference, I have a Dell M1530 dual boot Vista-Ubuntu. The hard drive is a Samsung HM160HI.

Edit:

Apparently half the problem was that I didn't (still somewhat don't) know how to interpret the data.

Thanks to everyone who gave me feedback.

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3 Answers 3

up vote 4 down vote accepted

Your Current Pending Sector Count (2163) is higher than the Reallocation Sector Count (252).
This means that failing sectors can no longer be replaced by the disk firmware.
The disk is failing - make sure you've backups, and get a replacement..

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From your data dump, the SMART Attribute value shows 100.
Therefore, this is not a problem flagged by SMART either.

Update: That 100 is an attribute -- it just indicates the health-status, not the count.
The worst value had been 100 too -- so, it never went lower.

For example, look at ID# 194, the temperature,
Raw value is 37, Attribute value is 127 and worst went in 90s.
Nothing to worry there too -- just an example on how to interpret attributes.
Again, the attribute value does not suggest your drive is running at 127C.


Couple of points from Wikipedia.

The inability to read some sectors is not always an indication that a drive is about to fail. One way that unreadable sectors may be created, even when the drive is functioning within specification, is through a sudden power failure while the drive is writing. In order to prevent this problem, modern hard drives will always finish writing at least the current sector immediately after the power fails (typically using rotational energy from the disk). Also, even if the physical disk is damaged at one location, such that a certain sector is unreadable, the disk may be able to use spare space to replace the bad area, so that the sector can be overwritten.

.

Number of "unstable" sectors (waiting to be remapped, because of read errors). If an unstable sector is subsequently written or read successfully, this value is decreased and the sector is not remapped. Read errors on a sector will not remap the sector (since it might be readable later); instead, the drive firmware remembers that the sector needs to be remapped, and remaps it the next time it's written.


Further on the down vote and comment.

  • A raw count at Current Pending Sectors usually implies sectors that are sort of written-off by the drive. This could be for various reasons that do not always imply an impeding disk failure.
  • If the raw count keeps increasing at regular intervals (days/weeks) it would then suggest a likely full disk failure. For example, do you recall (or have stored data) from an earlier check that shows this count to be lower or zero?
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Wait, so did I misread the dump? Is it that I have 252 Reallocated sectors and 100 pending? If so, should I still worry about the hard drive? –  Matthew Nov 13 '09 at 2:44
    
Short answer: No. Updated above. –  nik Nov 13 '09 at 2:53
    
Then what is the 2163 raw_value for current pending sector count supposed to be? According to Ubuntu's Palmipsest Disk Utility, it is something to worry about and a good reason to replace the disk, although I don't know whether I should completely trust said utility. –  Matthew Nov 13 '09 at 2:53
    
Short answer: No. The Attribute value is just a score. Not related to the raw data being tracked. Since the numbers can have different ranges and fluctuations for different parameters, a normalized scoring is used to show them (that is the attribute value). –  nik Nov 13 '09 at 2:55
    
I see. Thanks for all your help. –  Matthew Nov 13 '09 at 2:57

If the drive is under warranty, send it back for replacement. On a stable drive, that number should be 0, just like the Reallocated Sectors Count.

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