Re: ZFS RAIDZ2 and wd uncorrectable data error - why does ZFS not notice the hardware error?

[RVP <rvp%SDF.ORG@localhost>]

On Wed, 14 Jul 2021, Greg Troxel wrote:

> Good point.  I like to read all the way to the OS, and my way works on
> USB,

Ah, yes, USB drives... for them I have to use something like:

root# smartctl -d sat,12 -t offline /dev/XXX

The `12' is needed for my USB 1TB Maxtor. The standard 16 byte
commands don't work on it.

> but your suggested test can be faster and it's nice to get the
> stats recorded.

Actually, I find that it takes roughly about the same time (for
direcly-connected SATA drives).

> The drive reports at about 3-4 years of power on hours.
>
> >   9  74    0     no  online  positive    Power-on hours count        83567178701327
>
> wow, that's a lot!

That field is not quite that straight-forward to interpret. Some drives
report hours; some report those values in minutes or even half-minutes...
NetBSD's atactl just dumps the raw value, but smartctl corrects those using
its built-in drive database:

---
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   118   099   006    Pre-fail  Always       -       174942544
  3 Spin_Up_Time            0x0003   099   099   000    Pre-fail  Always       -       0
  4 Start_Stop_Count        0x0032   094   094   020    Old_age   Always       -       6688
  5 Reallocated_Sector_Ct   0x0033   100   100   036    Pre-fail  Always       -       0
  7 Seek_Error_Rate         0x000f   081   060   030    Pre-fail  Always       -       4451668093
  9 Power_On_Hours          0x0032   077   077   000    Old_age   Always       -       20742 (168 247 0)
 10 Spin_Retry_Count        0x0013   100   100   097    Pre-fail  Always       -       0
 12 Power_Cycle_Count       0x0032   094   094   020    Old_age   Always       -       6673
184 End-to-End_Error        0x0032   100   100   099    Old_age   Always       -       0
187 Reported_Uncorrect      0x0032   100   100   000    Old_age   Always       -       0
188 Command_Timeout         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   060   053   045    Old_age   Always       -       40 (Min/Max 37/41)
191 G-Sense_Error_Rate      0x0032   100   100   000    Old_age   Always       -       178
192 Power-Off_Retract_Count 0x0032   100   100   000    Old_age   Always       -       688
193 Load_Cycle_Count        0x0032   001   001   000    Old_age   Always       -       743554
194 Temperature_Celsius     0x0022   040   047   000    Old_age   Always       -       40 (0 19 0 0 0)
196 Reallocated_Event_Count 0x000f   079   079   030    Pre-fail  Always       -       18999 (27710 0)
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
240 Head_Flying_Hours       0x0000   079   079   000    Old_age   Offline      -       18999 (108 62 0)
241 Total_LBAs_Written      0x0000   100   253   000    Old_age   Offline      -       542484645
242 Total_LBAs_Read         0x0000   100   253   000    Old_age   Offline      -       15408048
254 Free_Fall_Sensor        0x0032   100   100   000    Old_age   Always       -       0
---


Cheers!
-RVP