Millibit would make sense in this discussion (since computers don't
deal with fractional bits), so obviously mb means megabyte, like tb
means terrabyte. I'm sloppy with capitals sometimes, sorry.
The "m" is not that bad, but "b" is bit while "B" is Byte.
I thought 3 MB was not really that much in proportion to the total
size of the drive (2 TB = 2 * 1024 * 1024 MB = 2097152 MB)
Defect sectors should be counted in number per device.
3MB is about 6000 defective secotrs, which is a massive
number. Typically drives are highly suspicuous from 10
defectives onwards and I have only seen one drive so far
with more than 50 defects that was not dying (it got
200 defects in a day and then never any additional ones,
I suspect vibration from some work being done next to the
computer).
[...]
How much redundant space does a typical 2 TB drive have to replace bad
sectors?
The drive was in operation on an uneven surface and perhaps it moved
around or bumped slightly
during operation.
I hope solid state disks will become more affordable soon, as they
seem more resilient to minor shocks.
The problem is less the reallocation space, and more that for each
defective sector there is a very real chance the data stored in it
is gone.
If you do a verify read that risk is mostly eleminated if the
reason is not a defective drive, but an environmental problem.
[...]
I have another screenshot that also shows the raw values.
Except for the temperature, the drive looks perfectly
healty. The temperature is 63C (if the encoding is
the same as on other WD drives) and 63C is deep
into HDD killer territory. More than 50C is reason
for real concern and typically above the maximum
allowed temperature. From 65-75C or so, the mechanics
and electronics starts to fail (non-permanently, but
ageing very fast, like beging dead from old age within
weeks-months), so that is possibly were your
defects came from: You got the disk so hot it
stopped working right.
You need to bring donwn the temperature.
The non-perfect scores on the "Worst" vlaue for
C5 and C8 indicate, there was a serious problem
but it is gone at the moment.
Well, in a typical situation, I might have the drive on the desk and
then being somewhat absent minded, I might be drumming along with some
music with my hands on the desk a bit too enthusiastically, which
might make the disk vibrate too much.
I dunno how sensitive these drives are and how much of a shock might
pose a serious problem during reading from or writing to the drive.
Maybe. Lound sounds can cause problems. Here is an
enlightening video demonstrating the effect:
This can also cause write defects, were the data is
unreadable (i.e. you have data loss) but the sector is again
fine after an overwrite.
Arno
