Home / server / Questions / 665880
In Process
Draemon
Asked: 2015-02-08 16:10:31 +0800 CST

How can a SMART normalised value be lower (worse) than the worst value?

  • 772

I'm seeing output from smartctl where the VALUE is much less than WORST for some attributes. Does this make sense? What does it mean?

Everything I have read indicates that:

  • The raw value (RAW_VALUE in smartctl output) is manufacturer specific but sometimes useful
  • The normalised value (VALUE in smartctl output) is normalised to the range 0..254 with higher always meaning better, but in a manufacturer specific way
  • The worst value seen by the drive is tracked (WORST in smartctl output)
  • If the current / worst value drops below the threshold (THRESH in smartctl output) and the attribute is a pre-fail attribute, it's a bad sign

I have a (believed healthy, if a little old) drive that has:

ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE
1 Raw_Read_Error_Rate     0x000f   200   200   051    Pre-fail  Always       -       0
3 Spin_Up_Time            0x0003   185   181   021    Pre-fail  Always       -       3725
4 Start_Stop_Count        0x0032   100   100   000    Old_age   Always       -       38
5 Reallocated_Sector_Ct   0x0033   200   200   140    Pre-fail  Always       -       0
7 Seek_Error_Rate         0x000f   200   200   051    Pre-fail  Always       -       0
9 Power_On_Hours          0x0032   076   076   000    Old_age   Always       -       17851
10 Spin_Retry_Count        0x0013   100   253   051    Pre-fail  Always       -       0
11 Calibration_Retry_Count 0x0012   100   253   051    Old_age   Always       -       0
12 Power_Cycle_Count       0x0032   100   100   000    Old_age   Always       -       36
190 Airflow_Temperature_Cel 0x0022   073   043   045    Old_age   Always   In_the_past 27
194 Temperature_Celsius     0x0022   120   090   000    Old_age   Always       -       27
196 Reallocated_Event_Count 0x0032   200   200   000    Old_age   Always       -       0
197 Current_Pending_Sector  0x0012   200   200   000    Old_age   Always       -       0
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   0x0009   200   200   051    Pre-fail  Offline      -       0

Which I interpret as everything's fine, although the drive got slightly too hot once (190 Airflow_Temperature_Cel).

My question is what's going on with lines 10 and 11 enter code herewhere WORST > VALUE?

smart

1 Answers

  1. In SMART normalized values (range: 1 .. 253), highest value is better, lower is worse. Manufacturers choose the initial normalized value, be it 253 (the maximul allowed value), 200, 100 (round numbers) or another number that suits them.

    Therefore 253 is better than 100. It would have made more sense to set both at 100 or 253, I guess the manufacturer didn't get picky about those details when ho wrote the firmware.

    • 2