James Courtier-Dutton wrote:
>
> I think people don't seem to realize that HDs have very low resistance
> to shock while switched on, and this is the main cause of HD failures.
> On the HDs that failed on you, were you able to determine the max G
> force that it received during its powered on life? I don't know how to
> get that information, but I am sure it would provide for some
> interesting stats. I think it would also be useful to have some study
> that would try and look into why HDs fail early in life, and thus try
> and recognize which ones are more likely to fail early. We might
> eventually get to the HAL 9000 prediction that a device is certain to
> fail in 72 hours, but until that time it will function normally.
>
>
Most (all?) modern HDDs have a whole raft of sensors and store life time
information about read errors, temperature range etc. etc. this is SMART
(you might see on the bios screen). In Linux you can query this using
smartctl:
~]# smartctl --all /dev/sda
For example the stats from my current drive here at work:
SMART Attributes Data Structure revision number: 10
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 108 093 006 Pre-fail
Always - 16203744
3 Spin_Up_Time 0x0003 098 095 070 Pre-fail
Always - 0
4 Start_Stop_Count 0x0032 100 100 020 Old_age
Always - 69
5 Reallocated_Sector_Ct 0x0033 100 100 036 Pre-fail
Always - 0
7 Seek_Error_Rate 0x000f 081 060 030 Pre-fail
Always - 139114079
9 Power_On_Hours 0x0032 088 088 000 Old_age
Always - 11202
10 Spin_Retry_Count 0x0013 100 100 097 Pre-fail
Always - 0
12 Power_Cycle_Count 0x0032 100 100 020 Old_age
Always - 99
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 061 057 045 Old_age
Always - 39 (Lifetime Min/Max 21/43)
194 Temperature_Celsius 0x0022 039 043 000 Old_age
Always - 39 (0 19 0 0)
195 Hardware_ECC_Recovered 0x001a 064 060 000 Old_age
Always - 164354431
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
You can see all sorts of interesting things here which can easily be
used to warn on pending failure of a drive.
Also most laptop drives now have accelerometers which will detect any
dangerous shock conditions and park the drive heads to prevent further
damage to the drive. I cannot find it now but I watched a video on the
web showing SSD vs HDD in a vibration test, the laptop was playing a
video and being vibrated... the SSD obviously didn't miss a beat, while
the HDD paused and stuttered but certainly didn't die, once the
vibration stopped everything returned to normal.
