GT said:
I have a friend with a hard drive that has developed bad sectors from
running over max temp for a while (probably the cause). Asuming the heat
problem is fixed, is the drive likely to survive, or will it keep developing
more bad sectors?
Don't need advice about new drives / backups etc - just opinion on whether
the damage will worsen or not.
I'm not aware of an easy mechanism, to get the drive to "recheck" the
spared out sectors. At least some drive technologies in the past,
allowed exactly that (I've done that at work, with SCSI drives in
the old days).
Most of the spared sectors, could now be in usage. The drive might be
happy to run that way. Or, the surface of the platters could be
degrading, with garbage flying around inside the housing. There is
no way externally, to know what is going on inside.
If you see "current pending" sector count continuing to grow,
it may imply there is still damage to be checked. What you can try
doing, is forcing a write to the entire disk, then restore the
user's data afterwards. If every sector is written at least
once, that gives time for the drive to "resolve" all current
pending (flaky) sectors. If errors continue to grow after
that, then you have to assume the drive is dirty inside.
The drive has air inside, at room temperature and pressure. Two
pieces of filter material are present inside the HDA. The air flows
around and around in there, and the air hits the filter material.
It allows debris to be trapped by the filter, to some extent.
Some drives, when opened up, are absolutely filthy, and
the interior of the drive is supposed to be Class 10 or
Class 100. So that tells you, why the drive died in the first
place. The heads can't become airborne off too many pieces of
that kind of debris, before being ruined permanently.
So you can do some testing for your friend. Erase the entire
drive, write back the user data, then do bad block scans for a
while to see how it's doing, then check SMART stats.
http://en.wikipedia.org/wiki/S.M.A.R.T.
197 Current Pending Sector Count
Count of "unstable" sectors (waiting to be remapped, because
of read errors). If an unstable sector is subsequently read
successfully, this value is decreased and the sector is not
remapped. Read errors on a sector will not remap the sector
(since it might be readable later); instead, the drive firmware
remembers that the sector needs to be remapped, and remaps it
the next time it's written.
What you want, is to not find Current Pending Sector Count growing,
after you've "flushed" the drive, and done some bad block scans.
Obviously, this is purely an academic approach, because if the user
doesn't do backups, this is the only copy, then a new drive is the
way to remove all doubt. Living with this drive as your sole copy,
is just asking for trouble. But I know you know that...
So
the above, is what I'd attempt in the name of being "thrifty".
Paul
