Error on calculation of "Last Test Age" in smart_report.sh #25
Description
The display of the Last Test Age was working for years without any issues.
On the last smart report i had this output:
+-------+------------------------+----+------+-----+-----+-------+-------+--------+------+----------+------+-----------+----+
|Device |Serial |Temp| Power|Start|Spin |ReAlloc|Current|Offline |Seek |Total |High | Command|Last|
| |Number | | On |Stop |Retry|Sectors|Pending|Uncorrec|Errors|Seeks |Fly | Timeout|Test|
| | | | Hours|Count|Count| |Sectors|Sectors | | |Writes| Count |Age |
+-------+------------------------+----+------+-----+-----+-------+-------+--------+------+----------+------+-----------+----+
|ada0 ? |WD-************ |39 | 65620| 186| 0| 0| 0| 0| N/A| N/A| N/A| N/A|2732*|
...
########## SATA drive /dev/ada0 Serial: WD-************
########## Western Digital Red (WDC ************)
SMART overall-health self-assessment test result: PASSED
ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE
1 Raw_Read_Error_Rate 0x002f 200 200 051 Pre-fail Always - 0
3 Spin_Up_Time 0x0027 182 173 021 Pre-fail Always - 3900
4 Start_Stop_Count 0x0032 100 100 000 Old_age Always - 188
5 Reallocated_Sector_Ct 0x0033 200 200 140 Pre-fail Always - 0
7 Seek_Error_Rate 0x002e 200 200 000 Old_age Always - 0
9 Power_On_Hours 0x0032 011 011 000 Old_age Always - 65620
10 Spin_Retry_Count 0x0032 100 100 000 Old_age Always - 0
11 Calibration_Retry_Count 0x0032 100 100 000 Old_age Always - 0
12 Power_Cycle_Count 0x0032 100 100 000 Old_age Always - 186
192 Power-Off_Retract_Count 0x0032 200 200 000 Old_age Always - 154
193 Load_Cycle_Count 0x0032 199 199 000 Old_age Always - 3283
194 Temperature_Celsius 0x0022 108 094 000 Old_age Always - 39
196 Reallocated_Event_Count 0x0032 200 200 000 Old_age Always - 0
197 Current_Pending_Sector 0x0032 200 200 000 Old_age Always - 0
198 Offline_Uncorrectable 0x0030 100 253 000 Old_age Offline - 0
199 UDMA_CRC_Error_Count 0x0032 200 200 000 Old_age Always - 0
200 Multi_Zone_Error_Rate 0x0008 200 200 000 Old_age Offline - 0
No Errors Logged
Test_Description Status Remaining LifeTime(hours) LBA_of_first_error
Short offline Completed without error 00% 61 -
On further analysis i found out that the S.M.A.R.T. LifeTime(hours) counter seems to have reset itself
/usr/local/sbin/smartctl -l selftest /dev/ada0
smartctl 7.2 2021-09-14 r5236 [FreeBSD 13.1-RELEASE-p2 amd64] (local build)
Copyright (C) 2002-20, Bruce Allen, Christian Franke, www.smartmontools.org
=== START OF READ SMART DATA SECTION ===
SMART Self-test log structure revision number 1
Num Test_Description Status Remaining LifeTime(hours) LBA_of_first_error
# 1 Short offline Completed without error 00% 61 -
# 2 Extended offline Completed without error 00% 65483 -
# 3 Short offline Completed without error 00% 65334 -
# 4 Short offline Completed without error 00% 65214 -
# 5 Extended offline Completed without error 00% 65099 -
# 6 Short offline Completed without error 00% 64974 -
# 7 Short offline Completed without error 00% 64854 -
# 8 Extended offline Completed without error 00% 64739 -
# 9 Short offline Completed without error 00% 64590 -
In this resource i got the explanation that this counter is normally stored in a 16 bit field but could also differ for different HDD vendors: https://serverfault.com/questions/1041661/s-m-a-r-t-lifetime-hours-resetting-to-zero
For me i could fix the issue by adding a modulo function in the calculation
testAge=sprintf("%.0f", ((onHours % 65535) - lastTestHours) / 24);
FreeNAS-scripts/smart_report.sh
Line 131 in 06ccffb