| 1 |
On Tue, Jun 23, 2020, at 12:26 PM, Dale wrote: |
| 2 |
> SMART can't predict the future so it can only monitor for the things |
| 3 |
> it can see. If say a spindle bearing is about to lock up suddenly, |
| 4 |
> SMART most likely can't detect that since it is a hardware failure that |
| 5 |
> can't really be predicted. We may be able to hear a strange sound if we |
| 6 |
> lucky but if it happens suddenly, it may not even do that. While SMART |
| 7 |
> can't predict all points of failures, it can detect a lot of them. Even |
| 8 |
> if the two drives I had failed with no warning from SMART, I'd still |
| 9 |
> run it and monitor it. Using SMART can warn you in certain situations. |
| 10 |
> If a person doesn't run SMART, they will miss those warnings. |
| 11 |
> |
| 12 |
> SMART isn't perfect but it is better than not having it all. |
| 13 |
> |
| 14 |
|
| 15 |
Well, in theory SMART should be able to predict hardware failures like |
| 16 |
that through N-th order effects that percolate up to read and write |
| 17 |
statistics. In practice it seems to be guessing badly. |
| 18 |
|
| 19 |
The danger of SMART is that rate of false negatives is so high (IME) that |
| 20 |
you might erroneously think a drive is not going to fail and putting off a |
| 21 |
backup. A good backup policy should mitigate this, but you still might plan |
| 22 |
around drive lifetime SMART predicts before realizing they are or can be |
| 23 |
bad predictions. |
Archives