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Today I noticed that in one SATA HD that I'm monitoring has the "Current_Pending_Sector" with RAW_VALUE=1 when inspecting the SMART attributes with smartmontools. Here is the output from smartctl.exe

SMART Attributes Data Structure revision number: 16
Vendor Specific SMART Attributes with Thresholds:
  1 Raw_Read_Error_Rate     0x000f   200   200   051    Pre-fail  Always       -       0
  3 Spin_Up_Time            0x0003   192   181   021    Pre-fail  Always       -       5366
  4 Start_Stop_Count        0x0032   100   100   000    Old_age   Always       -       158
  5 Reallocated_Sector_Ct   0x0033   200   200   140    Pre-fail  Always       -       0
  7 Seek_Error_Rate         0x000e   100   253   051    Old_age   Always       -       0
  9 Power_On_Hours          0x0032   076   076   000    Old_age   Always       -       18234
 10 Spin_Retry_Count        0x0012   100   100   051    Old_age   Always       -       0
 11 Calibration_Retry_Count 0x0012   100   100   051    Old_age   Always       -       0
 12 Power_Cycle_Count       0x0032   100   100   000    Old_age   Always       -       153
194 Temperature_Celsius     0x0022   110   105   000    Old_age   Always       -       40
196 Reallocated_Event_Count 0x0032   200   200   000    Old_age   Always       -       0
197 Current_Pending_Sector  0x0012   200   200   000    Old_age   Always       -       1
198 Offline_Uncorrectable   0x0010   200   200   000    Old_age   Offline      -       0
199 UDMA_CRC_Error_Count    0x003e   200   200   000    Old_age   Always       -       0
200 Multi_Zone_Error_Rate   0x0008   200   200   051    Old_age   Offline      -       0

Considering that this is a Windows 2008 server, what is the best way to deal with this problem?

Now the following message appeared in EventLog:

Device: C:, 2 Currently unreadable (pending) sectors (changed +1)
Device: C:, ATA error count increased from 1 to 5

It appears that the drive is slowly deteriorating, I think it's best to replace it.

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up vote 2 down vote accepted

There's basically two camps regarding non-failure SMART messages:

  • It's no big deal, no data was lost, the drive figured out that a couple sectors were going bad and dealt with them as it found appropriate.
  • No new is good new; everything else is a sign of imminent failure.

Personally I always run RAID and have regular, monitored backups to multiple mediums (on and off site). So I ignore pre-failure conditions; I use them until they're completely dead.

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Until now I haven't noticed any case of data loss nor errors in any of the applications that run in this computer. But you never know , so I will keep my eyes wide open. I have backups of everything that is in this disk but I wanna be prepared for the ocasion where the drive stops working. – Norba Jul 12 '11 at 18:19

Current Pending Sector means that the disk identified locations of the disk that are bad and wants to reallocate them. It probably can't read them though and so it waits until you write into them and then they will be reallocated. It will take slightly longer to write those locations once and then everything will be fine, most likely at least.

I can recommend using either diskscan for Linux or HD Tune for Windows to scan the disk surface and see if it detects an error. I believe both should be able to offer a correction mode to these locations so as to initiate a write to them and let the disk finish the reallocation.

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