Hard Drives and Smart.

Some Time ago i found a very interesting article from google about HDD's.
I was very surprised from some of the information i found in that document.

for example:

How smart is SMART?
Not very, as Google found, and many in the industry already knew. SMART (Self-Monitoring, Analysis, and Reporting Technology) captures drive error data to predict failure far enough in advance so you can back up. Yet SMART focuses on mechanical failures, while a good deal of a disk drive is electronic, so SMART misses many sudden drive failure modes, like power component failure. The Google team found that 36% of the failed drives did not exhibit a single SMART-monitored failure. They concluded that SMART data is almost useless for predicting the failure of a single drive.
So while your disk drive might crash without warning at any time, they did find that there are four SMART parameters where errors are strongly correlated with drive failure:

• scan errors
• reallocation count
• offline reallocation
• probational count

For example, after the first scan error, they found a drive was 39 times more likely to fail in the next 60 days than normal drives. The other three correlations are less striking, but still significant.
The bottom line: SMART can warn you about some problems, but miss others, so you can’t rely on it. So don’t. Back up regularly, and if you do get one of these errors, get a new drive.


 If you would like to read your S.M.A.R.T Infos just install "smartmontools".
"yum install smartmontools"

# smartctl -a /dev/sda

...

...

...

Will give you the information.


google HDD Study: Google HDD Research