Oh, here we go again. That stupid troll keeps doing it.
J. Clarke said:
Modern disks have spare sectors and map bad ones to spares automatically.
No they don't. They do it automatically on sectors *that are about to fail*
but don't yet fail completely.
This means that you never see a bad sector until the disk is in really bad shape,
Wrong again.
Uncorrectable read error bad sectors are *never* replaced automatically.
It takes a write to such sector.
The Clarke troll knows it because he has experienced that himself and is even
on record for it in Google.
so it seems to fail without warning.
SMART is intended to deal with this by providing you a warning when the disk
is starting to show signs of impending failure--it is built into the disk
and monitors a bunch of indicators, including the percentage of the spare
sectors that have been used--when it tells you that a disk is on the way
out, it's not a guarantee of impending failure--the disk may run in its
current condition for a very long time--but you were warned.
That message is actually from your computer's firmware--
or any SMART monitoring utility.
SMART doesn't say "this drive is about to go",
Wrong again. It *does* indicate that by providing a status :
The SMART ATA drive specification allows up to 30
internal drive measurements. These are termed failure
attributes and are periodically measured by a drive.
Attribute values are stored in the drive reserved data area
with other drive operational parameters. For a drive user to
receive a SMART warning the computer system must issue
specific drive interface commands to enable the algorithm
and then to read the resultant
* “won’t-fail/will-fail” * warning
Maximum thresholds are defined for each attribute by the
drive manufacturer.
The *SMART warning flag* is set in response to an
ATA SMART * “Return Status” * command,
if any attribute exceeds its threshold. This is a logical ‘OR’
operation among the several attribute threshold tests, and is
used because some drive failures may be predicted by only
one attribute.
*Threshold Exceeded Condition*
If one or more attribute values, whose Pre-failure bit of their
status flag is set, are less than or equal to their corresponding
attribute thresholds, then the device reliability status is *negative*,
indicating an *impending degrading or faulty condition*.
*SMART Return Status*
If the device does not detect a Threshold Exceeded Condition,
the device loads 4Fh into the Cylinder Low register and C2h
into the Cylinder High register.
If the device detects a Threshold Exceeded Condition, the
device loads F4h into the Cylinder Low register and 2Ch
into the Cylinder High register.
it just reports a bunch of numbers that if you have turned on the
capability get checked during the POST routine and if the combination
is such that your computer manufacturer's programmers have decided
that they indicate that the disk is having problems the machine will give
you the error message you see.
Wrong again.
It just translates the SMART Return Status into a user understandable message.
If it came up once and not again it's probably a fluke--
Nonsense.
something went wrong during power up that one time.
More likely an attribute counter that had crossed the treshold at that time,
to return into safe territory again later. If counters only counted backwards
there obviously wouldn't be a reason for "current" and "worst" value counters.
If it's happening most times that you power up then I'd replace the drive
at my earliest convenience. If you haven't shut the machine down and
rebooted since you saw it you should and see if it comes up again
Or use a S.M.A.R.T. monitoring app and do a 'Read Status'.