The 2007 google paper on failure trends in consumer-grade HDs lists 4 attributes that, once they fail, are indicative of a higher risk of HD failure in the next few months. These were the first occurence of: reallocated sectors, offline reallocations, scan errors, probational count.
http://labs.google.com/papers/disk_failures.pdfI'm trying to determine what these are called in the SMART attributes table on the NAS-M2's disk pages. I have 2 Maxtors and 1 Seagate HD in my NAS box. That way if I see one of these four in particular have failed I know I need to possibly come home and transfer that data right away.
MAXTOR
ID Attribute FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE
3 Spin_Up_Time 0x0027 219 219 063 Pre-fail Always - 12142
4 Start_Stop_Count 0x0032 252 252 000 Old_age Always - 2237
5 Reallocated_Sector_Ct 0x0033 253 253 063 Pre-fail Always - 0
6 Read_Channel_Margin 0x0001 253 253 100 Pre-fail Offline - 0
7 Seek_Error_Rate 0x000a 253 252 000 Old_age Always - 0
8 Seek_Time_Performance 0x0027 252 235 187 Pre-fail Always - 56334
9 Power_On_Minutes 0x0032 151 151 000 Old_age Always - 431h+34m
10 Spin_Retry_Count 0x002b 253 252 157 Pre-fail Always - 0
11 Calibration_Retry_Count 0x002b 253 252 223 Pre-fail Always - 0
12 Power_Cycle_Count 0x0032 253 253 000 Old_age Always - 91
192 Power-Off_Retract_Count 0x0032 253 253 000 Old_age Always - 0
193 Load_Cycle_Count 0x0032 253 253 000 Old_age Always - 0
194 Temperature_Celsius 0x0032 253 253 000 Old_age Always - 28
195 Hardware_ECC_Recovered 0x000a 253 252 000 Old_age Always - 13460
196 Reallocated_Event_Count 0x0008 253 253 000 Old_age Offline - 0
197 Current_Pending_Sector 0x0008 253 253 000 Old_age Offline - 0
198 Offline_Uncorrectable 0x0008 253 253 000 Old_age Offline - 0
199 UDMA_CRC_Error_Count 0x0008 199 199 000 Old_age Offline - 0
200 Multi_Zone_Error_Rate 0x000a 253 252 000 Old_age Always - 0
201 Soft_Read_Error_Rate 0x000a 251 248 000 Old_age Always - 2255
202 TA_Increase_Count 0x000a 253 252 000 Old_age Always - 0
203 Run_Out_Cancel 0x000b 253 252 180 Pre-fail Always - 0
204 Shock_Count_Write_Opern 0x000a 253 252 000 Old_age Always - 0
205 Shock_Rate_Write_Opern 0x000a 253 252 000 Old_age Always - 0
207 Spin_High_Current 0x002a 253 252 000 Old_age Always - 0
208 Spin_Buzz 0x002a 253 252 000 Old_age Always - 0
209 Offline_Seek_Performnce 0x0024 181 179 000 Old_age Offline - 0
99 Unknown_Attribute 0x0004 253 253 000 Old_age Offline - 0
100 Unknown_Attribute 0x0004 253 253 000 Old_age Offline - 0
101 Unknown_Attribute 0x0004 253 253 000 Old_age Offline - 0
SEAGATE
ID# ATTRIBUTE FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE
1 Raw_Read_Error_Rate 0x000f 119 099 006 Pre-fail Always - 215553792
3 Spin_Up_Time 0x0003 093 092 000 Pre-fail Always - 0
4 Start_Stop_Count 0x0032 100 100 020 Old_age Always - 32
5 Reallocated_Sector_Ct 0x0033 100 100 036 Pre-fail Always - 1
7 Seek_Error_Rate 0x000f 062 051 030 Pre-fail Always - 55858498415
9 Power_On_Hours 0x0032 091 091 000 Old_age Always - 8663
10 Spin_Retry_Count 0x0013 100 100 097 Pre-fail Always - 0
12 Power_Cycle_Count 0x0032 100 100 020 Old_age Always - 33
187 Unknown_Attribute 0x0032 100 100 000 Old_age Always - 0
189 Unknown_Attribute 0x003a 100 100 000 Old_age Always - 0
190 Unknown_Attribute 0x0022 062 050 045 Old_age Always - 690028582
194 Temperature_Celsius 0x0022 038 050 000 Old_age Always - 38 (Lifetime Min/Max 0/18)
195 Hardware_ECC_Recovered 0x001a 065 060 000 Old_age Always - 6630038
197 Current_Pending_Sector 0x0012 100 100 000 Old_age Always - 0
198 Offline_Uncorrectable 0x0010 100 100 000 Old_age Offline - 0
199 UDMA_CRC_Error_Count 0x003e 200 200 000 Old_age Always - 0
200 Multi_Zone_Error_Rate 0x0000 100 253 000 Old_age Offline - 0
202 TA_Increase_Count 0x0032 100 253 000 Old_age Always - 0
If I understand the manual, NAS-M2 will beep an error code if any of the atributes in this table are deemed to have failed. Correct ?
Reallocated sector count always has an entry, does this include offline reallocations ?
Which entry is for scan errors ? Is that the same as a seek error ?
Which entry is for probational count ?
Are any of these errors only detected through a smartctl --long self-test (I think those are the attributes marked UPDATED offline)? It appears that NASLite-M2 does NOT have smartd configured to run a self-test periodically.