Seagate disk SMART values...

I was just looking at smartctl output from one of my disks, and it had a large number for Seek error rate attribute (note that I edited the output for readability):

Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME          FLAG   VAL WOR THR TYPE     UPDATED WHEN_FAILED RAW_VALUE
  1 Raw_Read_Error_Rate     0x000f 100 253 006 Pre-fail Always      -       0
  3 Spin_Up_Time            0x0003 098 098 000 Pre-fail Always      -       0
  4 Start_Stop_Count        0x0032 100 100 020 Old_age  Always      -       826
  5 Reallocated_Sector_Ct   0x0033 100 100 036 Pre-fail Always      -       0
  7 Seek_Error_Rate         0x000f 072 060 030 Pre-fail Always      -       17262017054
  9 Power_On_Hours          0x0032 087 087 000 Old_age  Always      -       11538
 10 Spin_Retry_Count        0x0013 100 100 034 Pre-fail Always      -       0
 12 Power_Cycle_Count       0x0032 100 100 020 Old_age  Always      -       838
187 Reported_Uncorrect      0x0032 100 100 000 Old_age  Always      -       0
189 High_Fly_Writes         0x003a 100 100 000 Old_age  Always      -       0
190 Airflow_Temperature_Cel 0x0022 067 043 045 Old_age  Always  In_the_past 33 (0 17 33 31 0)191 G-Sense_Error_Rate 0x0032 100 100 000 Old_age  Always      -       0
192 Power-Off_Retract_Count 0x0032 100 100 000 Old_age  Always      -       809
193 Load_Cycle_Count        0x0022 001 001 000 Old_age  Always      -       351945
194 Temperature_Celsius     0x001a 033 057 000 Old_age  Always      -       33 (0 11 0 0 0)195 Hardware_ECC_Recovere 0x0012 097 044 000 Old_age  Always      -       196225726
197 Current_Pending_Sector  0x0010 100 100 000 Old_age  Offline     -       0
198 Offline_Uncorrectable   0x003e 100 100 000 Old_age  Always      -       0
199 UDMA_CRC_Error_Count    0x0000 200 200 000 Old_age  Offline     -       1
200 Multi_Zone_Error_Rate   0x0032 100 253 000 Old_age  Always      -       0
202 Data_Address_Mark_Errs  0x0000 100 253 000 Old_age  Offline     -       0
254 Free_Fall_Sensor        0x0000 100 253 000 Old_age  Offline     -       0

It's not the first time I saw such a large raw values which, while not problematic (VAL/WOR/THR should be actually monitored) are nevertheless interesting, to say at least. While searching around I stumbled on a post Seagate's Seek Error Rate, Raw Read Error Rate, and Hardware ECC Recovered SMART attributes. In this post, the author explains that all the values are actually 48 bits, and due to the way they are encoded it follows that those values are large. More specifically, raw value of the Seek error rate attribute should be converted to hexadecimal and then upper 16 bits are number of errors, while lower 32 bits are total number of seeks.

In this concrete case the raw value for Seek error rate is 17262017054, or 0x000404E57A1E. The first 16 bits is 0x0004 and the last 32 bits are 0x04E57A1E. What this means is that there were 4 seek errors (meaning the head wasn't positioned correctly after being moved to some track) but there were 82147870 seeks in total. So, this is very very small fraction of errors.

For the meaning of Seek error rate attribute, and many others, I recommend Wikipedia's page about SMART.