Need second opinion, is my HD failing?

[Bryn M. Reeves]

Paulo Cavalcanti wrote:
> But in Richard's case, 955 seems odd to me:
> 
> 5 Reallocated_Sector_Ct   0x0033   100   100   036    Pre-fail    Always
>   -       955
> 
> Probably, you are right, and the value is OK. But I have never seen a
> counting like
> this before. I had a defective disk once, which increased 20 or 30 bad
> sectors a day.
> Therefore, such a high score would not be a surprise for me (Seagate
> replaced the disk for me,
> even it being more than 2 years old).

It is quite a high number and many of my drives do have raw values 
much closer to zero, although I have at least a few with raw values in 
the 100s that still have 100 as the normalised value and are working fine.

The problem with trying to interpret the raw values is that they are 
completely under the control of the vendor. The only thing S.M.A.R.T. 
specifies is the size of the field. Some vendors have previously taken 
a single field and used it to encode multiple values (e.g. breaking it 
up into several sub-fields). For example, some IBM drives encode three 
distinct temperature measurements in the raw value for the 
Temperature_Celsius attribute.

Because of this, unless you know the scheme being used for a given 
vendor/drive model it's impossible to make any accurate assumption 
from the raw value alone - you just have to trust the firmware to 
decrement the normalised value appropriately as the drive begins to 
deteriorate.

Regards,
Bryn.