Is there enough information for SMART to determine the health of the drive?

Question

linux

Hello!
Please share your experience.
1. Is there enough information for SMART to determine the status of the drive?
2. What SMART values ​​should be guided by when deciding to replace the drive? How big should the values ​​be?
3. SAS disks have a different output of SMART information, what values ​​​​to focus on in this case?
Thank you!

Answer 1

1. No, not enough. You can focus on them, but disks can fly out with a perfect smart.
2. www.ixbt.com/storage/hdd-smart-testing.shtml
From experience, you can't really look at the raw read error rate and Seek Error Rate, only if the smart itself swears at them.
The most critical: 05, 184, 187, 196, 197, 198, 200
It is worth monitoring the temperature (so that it does not exceed the allowable limit according to the documentation of a particular model) and 199
3. SAS usually has only a simplified smart.
Elements in grown defect list - a non-zero value is not very good, but not critical (because the error correction algorithm could work normally and this is just a reassigned sector).
Errors Corrected by delayed- also not very good.
Total Errors - definitely bad.

Answer 2

1. no. because SMART will not tell you about the state of the hard disk surface, at least not exhaustively.
2.

Raw Read Error Rate - error rate when reading data from a disk, the origin of which is determined by the disk hardware.
Spin Up Time - time to spin up a pack of disks from rest to operating speed. When calculating the normalized value (Value), the practical time is compared with some reference value set at the factory. A non-deteriorating non-maximum value with Spin Up Retry Count Value = max (Raw equal to 0) does not mean anything bad. The difference in time from the reference can be caused by a number of reasons, for example, a drawdown in the voltage of the power supply.
Spin Up Retry Count - the number of retries to spin up disks to operating speed, if the first attempt was unsuccessful. A non-zero Raw value (respectively, a non-maximum Value) indicates problems in the mechanical part of the drive.
Seek Error Rate - error rate when positioning the block of heads. A high Raw value indicates the presence of problems, which may be damaged servos, excessive thermal expansion of disks, mechanical problems in the positioning unit, etc. A constantly high Value indicates that everything is fine.
Reallocated Sector Count - number of sector remapping operations. SMART in modern disks is able to analyze the sector for stability on the fly and, if it is recognized as a failure, reassign it.
3. don't know

Answer 3

for all parameters
if one is bad, then the disk must be changed