Instruction of interpretation of hard drive self test stats

[wpshooter]

Are there any instructions / info on the meaning of all the data that is given
on the hard drive self tests that is found on Linux Mint ?

The reason I ask is because when I look at the resulting data from a drive
that I am running the test on, in most of the categories the WORST is higher
than the THRESHOLD, yet the final report of the self-test says that the drive
is OK and did not exceed threshold and all of the status listings on the far right column also say OK.

Are these threshold listings just a DESIRED result and higher result are
acceptable just not desired ?

Thanks.

[Mute Ant]

The SMART statistics are presented so that a perfect drive scores 100% for all the parameters. If the drive starts to develop weaknesses, like sectors that stop being recordable, the raw "Fault" count goes up and the 100% comes down a little bit... the drive is not perfect any more. Eventually a score will drop under the threshold and the report starts warning 'Not Okay Any More' or even 'Imminent Failure'.

Wiki usually has something relevant...
https://en.wikipedia.org/wiki/S.M.A.R.T.
...especially...
If SMART says the drive is failing it's probably right.
If SMART says the drive is okay, there's a 50% chance it's wrong i.e. 50% of drives fail without triggering a SMART failure.

Very (very) approximately, half the magnetic drives working today will have failed 6 years from now. Using or not-using the drive doesn't seem to make any difference.

[wpshooter]

The SMART statistics are presented so that a perfect drive scores 100% for all the parameters. If the drive starts to develop weaknesses, like sectors that stop being recordable, the raw "Fault" count goes up and the 100% comes down a little bit... the drive is not perfect any more. Eventually a score will drop under the threshold and the report starts warning 'Not Okay Any More' or even 'Imminent Failure'.

Wiki usually has something relevant...
https://en.wikipedia.org/wiki/S.M.A.R.T.
...especially...
If SMART says the drive is failing it's probably right.
If SMART says the drive is okay, there's a 50% chance it's wrong i.e. 50% of drives fail without triggering a SMART failure.

Very (very) approximately, half the magnetic drives working today will have failed 6 years from now. Using or not-using the drive doesn't seem to make any difference.

At present day technology, do SSD have a higher or lower life expectancy than mechanical drives ?

Thanks.

[Mute Ant]

Good News: The data-sheet promises suggest that modern SSD and mature HDD are now roughly equal in reliability.

You should look at the MTBF or AFR for the drive, then add a huge pinch-of-salt to guess how long it will actually last in service.

"Annualized failure rate (AFR) gives the estimated probability that a device or component will fail during a full year of use."
https://en.wikipedia.org/wiki/Annualized_failure_rate

http://knowledge.seagate.com/articles/e ... uage=en_US

2009: Magnetic: 2TB: AFR 0.32%
https://www.seagate.com/docs/pdf/datash ... uda_lp.pdf

2011: Magnetic: 3TB: AFR < 1%
https://www.seagate.com/staticfiles/doc ... 1111us.pdf

2017: Silicon: 1.9TB: AFR 0.44% <----- Calculated from MTBF of two million hours with AFR=(365)*(24)/(MTBF)
https://www.intel.co.uk/content/www/uk/ ... h-3d1.html

So SSD and HDD promise a similar yearly survival... After 1 year 1% will fail and 99% will still work.
-----> 2 years 98%
-----> 8 years 92%
-----> 32 years 72%
-----> 69 years 50%

Bad News: AFR is optimistic by a factor of ten-times the real-world results from BackBlaze, who monitor thousands of desktop-grade magnetic drives doing real work.
After 6 years 50% are still working
-----> 1 year 89%
-----> The Real World AFR for magnetic drives is 11%.

Time for a new edition perhaps...
https://images-eu.ssl-images-amazon.com ... SY346_.jpg