Which attributes can estimate number of bad blocks?

To get a quick estimate of the number of bad blocks that have already been detected, I add the raw values of attributes 5 (Reallocated_Sector_Ct) and 197 (Current_Pending_Sector).

Should I also add the raw values of attributes 187 (Reported_Uncorrect) and 198 (Offline_Uncorrectable)?  Or are these redundant, already included in attributes 5 and 197?

Are there others that I should add?

Of course this estimate isn't as reliable as ... well actually, other methods of testing aren't particularly reliable either[*].  Anyway the reason for getting a quick estimate is that if we know quickly that a drive belongs on the scrap heap, it saves time.

[* I have a drive with particularly bad firmware.  Reading the entire drive causes Current_Pending_Sector to increase.  Writing the bad sectors doesn't cause Reallocated_Sector_Ct to increase but does cause Current_Pending_Sector to go down to 0.  I guess the drive thinks that a write operation fixed the sector so the sector doesn't need reallocation, but the next attempt to read shows that the sector didn't get fixed.  If the drive were in warranty, I might not have it any more :-) ]


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