hard drive pending sector count

Question

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.

Answer 1

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..

Answer 2

I'm new here, with no reputation, so I cannot affect the rating of answers above, but the green checked answer of Nov 13, 2009 at 8:42 is almost completely wrong! The first 2 sentences are completely wrong, comparing apples (raw count of 2163) to oranges (normalized score of 252). Reallocated_Sector_Ct is zero! That means not one sector has been remapped yet! And the Current_Pending_Sector count of 2163 sectors are questionable sectors, but not necessarily unusable sectors. They are not reclaimed or remapped until a write is made to the questionable sector, at which point the drive stops trying to preserve the contents of the sector and can thoroughly test its media, and decide whether to put it back online as good, or remap it, reallocating a spare sector into its LBA.

Sector data can be scrambled by power spikes, which cause them to fail their ECC info, and be marked as a Current_Pending_Sector. The next write will allow the drive to discover that the underlying media is fine, and reuse the sector, writing fresh data with fresh ECC info.

Please read the Wikipedia article on "S.M.A.R.T."

A Current_Pending_Sector count of 2163 is very worrying, and even more so is an Offline_Uncorrectable count of 19080. While not critical, a G-Sense_Error_Rate that is maxed out at 999999 is also somewhat alarming. That's a lot of physical jolts!

Answer 3

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.

Answer 4

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.

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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.

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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?