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Sid Spry wrote: |
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> |
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> On Tue, Jun 23, 2020, at 12:26 PM, Dale wrote: |
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>> SMART can't predict the future so it can only monitor for the things |
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>> it can see. If say a spindle bearing is about to lock up suddenly, |
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>> SMART most likely can't detect that since it is a hardware failure that |
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>> can't really be predicted. We may be able to hear a strange sound if we |
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>> lucky but if it happens suddenly, it may not even do that. While SMART |
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>> can't predict all points of failures, it can detect a lot of them. Even |
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>> if the two drives I had failed with no warning from SMART, I'd still |
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>> run it and monitor it. Using SMART can warn you in certain situations. |
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>> If a person doesn't run SMART, they will miss those warnings. |
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>> |
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>> SMART isn't perfect but it is better than not having it all. |
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>> |
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> Well, in theory SMART should be able to predict hardware failures like |
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> that through N-th order effects that percolate up to read and write |
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> statistics. In practice it seems to be guessing badly. |
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> |
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> The danger of SMART is that rate of false negatives is so high (IME) that |
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> you might erroneously think a drive is not going to fail and putting off a |
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> backup. A good backup policy should mitigate this, but you still might plan |
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> around drive lifetime SMART predicts before realizing they are or can be |
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> bad predictions. |
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> |
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> |
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Thing is, drives fail at some point. SMART, while not perfect, can |
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detect problems that indicate a failure. Let's say for example a person |
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because of the false positives decides not to run SMART at all. What |
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are they going to use to figure out if a drive is working like it |
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should? Is a drive having problems reading, writing or noticing corrupt |
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data that is a sign of a problem? Is it about to fail somehow? It's |
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not like there is really any other tool that does this. if one doesn't |
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use the tool, they can have a failure that they could have been warned |
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about and not lose data or very little data. If a person runs it tho, |
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at least they have something that can detect some failures and prevent |
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data loss. |
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It's safer to run SMART and get notified when it detects a problem than |
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it is to not run it and have no way of knowing there is a problem at |
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all. Sure, backups are something everyone should do for important |
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data. I have backups here, multiple backups of some data. Still, I run |
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SMART and pay attention to the emails it sends when something is not |
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right. In the past, it has saved me from data loss. |
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I'm sure there is many false positives out there but ignoring the real |
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positives isn't a good solution either. By all means, if one wants to |
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just wing it and hope for the best, disable SMART and take the risk. At |
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some point, a drive will fail and without SMART, likely with no warning |
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at all, not even a false one. ;-) |
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Dale |
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:-) :-) |
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