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Old September 10th 16, 01:44 PM posted to alt.windows7.general,comp.sys.ibm.pc.hardware.storage
Linea Recta[_2_]
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Default is my C drive dying?

"Paul" schreef in bericht
...
Linea Recta wrote:
My PC had always been very sluggish compared to my old laptop.
When reading a PC magazine I read an article about Crystal diskinfo.
Decided to download the portable version ans ran it on the laptop:
diagnose OK.

Decided to run it also on the PC: WARNING for the C drive! (see below)
Is my C drive dying?
Apart from fitting a new drive this is going to be A LOT of work,
installing and updating Windows 7 and A LOT of applications!
I suppose I can't restore a Macrium image on the replacement drive?


Be aware that "Reallocated Sector Count" does not mean
data is corrupted. It means a sector was detected as
being less than functional, and was replaced by a
spare. Only a certain percentage of the total drive
capacity is available for sparing, so it will run
out eventually.

If you were to scan the drive and found no CRC errors,
you could easily make a backup of the drive as it stands.
Then restore the drive to a replacement hard drive. No
need to reinstall an OS or anything. Just use your
backup/restore program in Clone mode.

Take the following information, collected over three days.

Current Worst Threshold Data Status
Reallocated Sector Count 100 100 36 0 OK
Reallocated Sector Count 100 100 36 57 OK
Reallocated Sector Count 98 98 36 104 OK

On the third day, drive life is at 98%, and there are
104 reallocated sectors. That implies the spare sector
count remaining is roughly 5000 sectors (spread over the disk, not
all in one spot). I have used up 2% of them.

The reallocations tend to show up, if I write the drive
from end to end. I tend to see more of them after writing
the whole drive.

Note that the top line implies "perfect health". But the
whole thing is a sham. The reading is actually thresholded.
No drive leaves the factory in "perfect" condition. So
what you're looking at, is a portion of drive life.
The reason the statistic is not entirely accurate, is to
prevent buyers from "cherry picking" drives. If the
actual number of reallocations appeared in SMART,
people would keep returning drives until they got
one with a relatively low number of reallocations.
As a result, the drive appears defect-free for a long
period of time. Maybe after 100,000 sectors have been
spared, the last 5000 spares are recorded in the above
fashion. All I can tell you, is the observed behavior
does not match what is known about hard drives. That
field is "cooked". The field has diagnostic value,
but the scale is not "linear".

I've even had cases of "degraded" write speed on a
hard drive, only to see this in SMART. I.e. Perfect Health.
The Data field is the one with the defect count in it. SMART
is only really effective, if the reallocations are
spread smoothly over the disk, so no one tiny area
of the disk is slowed down. Reallocations make the disk
slower.
Current Worst Threshold Data Status
Reallocated Sector Count 100 100 36 0 OK

If I run out of spare sectors, and a sector is defective,
I could eventually see the sector throw a CRC error, because
the error pattern in it was too great for error correction
to fix.

Nothing prevents data from being corrupted, even when the
drive is new. The datasheet for the drive, lists the
corrected and uncorrected error rates to be expected.
However in practice, you'd be hard pressed to see the
background error rate, if it exists. Error correction
seems to do a good job (and costs some of the drive
capacity, to add that feature). Just as an SSD might have
25 bytes of ECC per 512 byte flash sector, for a total
of 537 bytes per sector of storage. If you cut the
drive capacity in half, you could allocate half of the
drive, just for the ECC bits. And give a very strong
data correction capability. For each generation of
drive (with new, flaky recording method), they figure
out the right number of ECC bits to add for that
generation. It's not necessarily a constant
percentage of overhead.

*******

Download HDTune 2.55 and use the Health tab to verify
your findings. Take a picture of the screen with the
Health tab showing, and present the link here.

http://www.hdtune.com/files/hdtune_255.exe



Thanks for the crash course!
But VirusTotal gives 2 hits for this file... so I haven't installed it yet.

BTW could you explain (briefly) the difference between cloning and restoring
a drive?

Another thing: I also have 2 external USB hard drives. One tested OK, but
the other (Maxtor onetouch) isn't even detected by Crystal diskinfo. (it's
still working ok though)



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(Example of an image hosting site, for your screenshot.
Use the snippingtool in Win7 for example, to take a picture.)USB
https://postimage.org/index.php?um=flash

In this picture, the drive shows 9 reallocations.
And since the health is still 100%, it's not in
real trouble yet. You would at least make sure you
have one recent full backup, stored on another disk.

http://atm.cyberec.com/~hello/pictures/Clipboard01.jpg

This is the boot drive on this computer, as recorded
some time ago. Both reallocated and current pending are 0.
On some brands of drives, current pending never goes
non-zero, until, perhaps, the drive has run out of
spare sectors. On other brands of drives, current
pending works properly. I mainly rely on the
reallocated field as a result. The brand in the
above picture, apparently has a working Pending field.

https://s33.postimg.io/ee9ti1m67/startstop.gif

Note - SMART wasn't working properly on Windows 10
for a number of releases. It might be fixed now.
On the other Windows OSes, while the HDTune window
itself may show some weird behaviors, the data readout
is OK.

If you happen to own the Pro version of HDTune,
then you can use that instead.

*******

This should not be a lot of work to fix. Just clone
the broken drive to a new drive - all done.

But one of your drives is Maxtor brand, and since
I've had a few of those die overnight, I don't
particularly trust those further than I can
throw them :-( While some of my 500GB Seagates are
a bit smelly (show non-zero reallocation count),
they're not dead, which says a lot about them.
They don't seem to drop dead.

If the lubricant in the hub motor is gone, the
motor can seize instantly. I had one drive squeak
at startup, but it stopped a few days late.
No idea what that means. I have the word "squeak"
written on the top of the drive, so if it
dies some day, then I'll have some idea why.
We used to blame such noises, eons ago, on the
antistatic spring contact, but they don't use those
any more as far as I know.

Paul