WD drives have errors caused by CRT


B

Ben Bradley

I'll ask the question I can get an answer for first, and describe
the background/rant/how it happened further down.
I have WD400 and WD800 EIDE drives that scandisk has detected
hundreds of bad clusters on. Watching its operation (W98, running
scandisk in dos mode), if it is unable to read a cluster in about ten
seconds, it marks it bad, which is fine. Unfortunately there are many
clusters adjacent to the bad ones that scandisk reads good, even
though it may take 1 to 5 seconds to read it. When scandisk reads
through a good/unaffected area of the disk, it reads about 100
clusters per second (or about 10mS per cluster). I would like to have
these "adjacent blocks" that take substantially more than 10mS to read
to also be marked bad. Is there a utility that will do this?
My reason for wanting to do this is so I can use the machine for
recording LP's and 78's, and burning the recordings to CDR. These are
basically real-time tasks (though of course highly buffered for the
non-RT desktop OS), and I don't want to have it fail because a block
from the hard disk ends up taking several seconds to read or write.

So here's how it happened/the rant:

I have a Dell XPS T400 (Pentium II, 400MHz) system I bought cheap
without drives and added two older drives I had from upgrading other
machines. They are WD400 and WD800 EIDE drives about three to four
years old, with no bad areas (at least as seen by Windows 98's
scandisk). I've had this system up on a bench for a few months and the
drives have been doing fine according to the occasional scandisk run.
A couple of weeks ago I relocated the monitor (an IBM VGA, with the
slanted IBM PS2 logo) next to the right side of the computer, cases
separated by about an inch. After moving the monitor, the computer
was on all the time and the monitor was on for most of this time.
Several days after moving the monitor I ran scandisk on one drive and
was surprised to see a LOT of bad blocks, and I ran it on the other
drive and saw many bad blocks on it as well.
I at first thought an electrical spike might have caused this, but
then I observed that it corresponded to moving the monitor next to the
machine. I moved the monitor away and ran scandisk on each drive a
couple more times, and a few more marginal "adjacent blocks" were
detected as bad each time, but these are a small number (maybe 10-20)
compared to the first time I saw the problem (hundreds). So as I see
it this was clearly caused by the proximity of the monitor (perhaps
the horizontal and/or vertical deflection yokes continuously
generating large alternating magnetic fields, or maybe the degaussing
coil when the monitor is turned on).
After some googling for disk utility programs, I downloaded and ran
diagnostic programs from Western Digital and Maxtor. Both programs run
fine on this machine (Dell XPS T450, W98) and both drives (IBM 28 gig,
original drive from 1999! and new WD 120 gig) show as perfect in all
tests. On the machine in question they can read the SMART data, but of
course find enough errors on full disk scan to say "This drive is
failing."
I had one utility do a "write zeros" to Drive D: (the 80 gig), did
an FDISK to reestablish it as a DOS drive, then did a DOS/Windows
Format to clean it off and put a filesystem on it. Running scandisk on
this just ends up rediscovering all the bad blocks that it had found
before (all the B's are showing up in the same place as before on this
drive). Currently scandisk shows out of 2,441,533 clusters, 427,000
examined, 670 found bad.
I've read about 'spare tracks' (drives internally have
substantially more storage than advertised, and use this space to
invisibly replace failing/marginal tracks), but I don't know of a way
to tell how many of these are actually being used in a 'perfect'
drive. I presume there's some utilities to show total spare tracks and
how many are in use - what program does that? (not that it would help
me here, this is just general interest) Apparently all the 'spare
tracks' on these two drives are all used up.
These errors on the disk are apparently 'soft' in that they are
caused by bad data written to the disk, and not by bad media itself,
so if these areas could be rewritten, these spots could be fixed. I
looked up low-level formatting in hopes of doing that, and it's clear
that you can't low-level format modern drives.
And so, these drives were made pretty much FUBAR just by putting a
running CRT monitor next to the PC case for a few days. Is it common
knowledge that this can happen? I'm really surprised I haven't heard
about it. I didn't even think of possible drive damage when I put the
monitor there. Hard disk drives are put next to rotating fans and
switching power supplies very often, and those things generate
magnetic fields, and are supposed to have high coercivity and be
diffucult to erase. Perhaps long-term they DO cause errors in hard
disk drives, and no one has noticed or tied it to adjacent devices
creating magnetic fields.

I can already hear the responses "go buy a new computer, they're
cheap enough..."
 
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A

Arie Bant

I'll ask the question I can get an answer for first, and describe
the background/rant/how it happened further down.
I have WD400 and WD800 EIDE drives that scandisk has detected
hundreds of bad clusters on. Watching its operation (W98, running
scandisk in dos mode), if it is unable to read a cluster in about ten
seconds, it marks it bad, which is fine. Unfortunately there are many
clusters adjacent to the bad ones that scandisk reads good, even
though it may take 1 to 5 seconds to read it. When scandisk reads
through a good/unaffected area of the disk, it reads about 100
clusters per second (or about 10mS per cluster). I would like to have
these "adjacent blocks" that take substantially more than 10mS to read
to also be marked bad. Is there a utility that will do this?


Low level formatting should do the job.
Most disk manufacturers have a special program that will initiate a low
level format on the drive. Have you tried finding that on the WEB-site
or asking their Technical support people?
You may find something on one of the generic download sites for
utilities such as download.com
Good Luck!

Arie Bant.
 
R

Ron Reaugh

Arie Bant said:
Low level formatting should do the job.
Most disk manufacturers have a special program that will initiate a low
level format on the drive.

No, only SCSI has that generally. ATA HDs mfgs just supply utilities
that'll write zeroes to all the sectors.
 
R

Rod Speed

No, only SCSI has that generally. ATA HDs mfgs
just supply utilities that'll write zeroes to all the sectors.

They do more than that, they also add new bad sectors to the bad sector list.
 
R

Ron Reaugh

Rod Speed said:
They do more than that, they also add new bad sectors to the bad sector
list.

Any write-read that indicates a weak sector does that. Do you know what the
classic meaning of low level format is?? Do you know how to get sectors out
of the bad sector list?? Do you have your speedo on backwards?
 
F

Folkert Rienstra

Ben Bradley said:
I'll ask the question I can get an answer for first, and describe
the background/rant/how it happened further down.
I have WD400 and WD800 EIDE drives that scandisk has detected
hundreds of bad clusters on. Watching its operation (W98, running
scandisk in dos mode), if it is unable to read a cluster in about ten
seconds, it marks it bad, which is fine. Unfortunately there are many
clusters adjacent to the bad ones that scandisk reads good, even
though it may take 1 to 5 seconds to read it. When scandisk reads
through a good/unaffected area of the disk, it reads about 100
clusters per second (or about 10mS per cluster). I would like to have
these "adjacent blocks" that take substantially more than 10mS to read
to also be marked bad. Is there a utility that will do this?
My reason for wanting to do this is so I can use the machine for
recording LP's and 78's, and burning the recordings to CDR. These are
basically real-time tasks (though of course highly buffered for the
non-RT desktop OS), and I don't want to have it fail because a block
from the hard disk ends up taking several seconds to read or write.

So here's how it happened/the rant:

I have a Dell XPS T400 (Pentium II, 400MHz) system I bought cheap
without drives and added two older drives I had from upgrading other
machines. They are WD400 and WD800 EIDE drives about three to four
years old, with no bad areas (at least as seen by Windows 98's
scandisk). I've had this system up on a bench for a few months and the
drives have been doing fine according to the occasional scandisk run.
A couple of weeks ago I relocated the monitor (an IBM VGA, with the
slanted IBM PS2 logo) next to the right side of the computer, cases
separated by about an inch. After moving the monitor, the computer
was on all the time and the monitor was on for most of this time.
Several days after moving the monitor I ran scandisk on one drive and
was surprised to see a LOT of bad blocks, and I ran it on the other
drive and saw many bad blocks on it as well.
I at first thought an electrical spike might have caused this, but
then I observed that it corresponded to moving the monitor next to the
machine. I moved the monitor away and ran scandisk on each drive a
couple more times, and a few more marginal "adjacent blocks" were
detected as bad each time, but these are a small number (maybe 10-20)
compared to the first time I saw the problem (hundreds). So as I see
it this was clearly caused by the proximity of the monitor (perhaps
the horizontal and/or vertical deflection yokes continuously
generating large alternating magnetic fields, or maybe the degaussing
coil when the monitor is turned on).
After some googling for disk utility programs, I downloaded and ran
diagnostic programs from Western Digital and Maxtor. Both programs run
fine on this machine (Dell XPS T450, W98) and both drives (IBM 28 gig,
original drive from 1999! and new WD 120 gig) show as perfect in all tests.
On the machine in question they can read the SMART data, but of
course find enough errors on full disk scan to say "This drive is failing."
I had one utility do a "write zeros" to Drive D: (the 80 gig), did
an FDISK to reestablish it as a DOS drive, then did a DOS/Windows
Format to clean it off and put a filesystem on it. Running scandisk on
this just ends up rediscovering all the bad blocks that it had found
before (all the B's are showing up in the same place as before on this
drive). Currently scandisk shows out of 2,441,533 clusters, 427,000
examined, 670 found bad.
I've read about 'spare tracks' (drives internally have
substantially more storage than advertised, and use this space to
invisibly replace failing/marginal tracks), but I don't know of a way
to tell how many of these are actually being used in a 'perfect'
drive. I presume there's some utilities to show total spare tracks and
how many are in use - what program does that? (not that it would help
me here, this is just general interest) Apparently all the 'spare
tracks' on these two drives are all used up.
These errors on the disk are apparently 'soft' in that they are
caused by bad data written to the disk, and not by bad media itself,

Apparently not, in your case.
so if these areas could be rewritten, these spots could be fixed.

You've done that. From what you're saying, it didn't resolve the problem.
Apparently the spots are weak.
I looked up low-level formatting in hopes of doing that, and it's clear
that you can't low-level format modern drives.

No, that is not clear. Not that it matters. The sparing system is in
essence a LLF on the single sector level. Writing zeroes to bad sector
candidates is doing a selective LLF.
 
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F

Folkert Rienstra

Rod Speed said:
They do more than that, they also add new bad sectors to the bad sector list.

No, they don't. Only a real LLF did that and most drives don't allow that
anymore. Drives do it themselves now when reassigning bad sectors on the go.
 
R

Rod Speed

Any write-read that indicates a weak sector does that.

Its more complicated than that.
Do you know what the classic meaning of low level format is??
Yep.

Do you know how to get sectors out of the bad sector list??

Irrelevant to what is being discussed.
 
R

Rod Speed

Folkert Rienstra said:
Apparently not, in your case.
You've done that. From what you're saying, it didn't resolve the problem.
Apparently the spots are weak.

Impossibly unlikely that that many would all go weak at once.
No, that is not clear. Not that it matters. The sparing system
is in essence a LLF on the single sector level. Writing zeroes
to bad sector candidates is doing a selective LLF.

Its more complicated than that if what appears to be
bad varys due to that being due to external factors.
 
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B

Ben Bradley



That's one of several sites I found while researching this problem,
and that page doesn't seem to say much. The LLF programs they have are
very old and meant for older drives that had the capability of being
LLF'ed in the field. It appears that recent (in the last 10-15 years
or so) drives intentionally don't have that capability.
 
B

Ben Bradley

Low level formatting should do the job.

I agree it would, it appears the sector marks and such are
corrupted, and nothing else will fix that. More googling didn't really
find any "low-level format" utility that will do these drives, but it
appears a lot of people are confused between doing a "write zeroes"
and a low-level format. What's worse is the Western Digital website
adds to the confusion:

http://wdc.custhelp.com/cgi-bin/wdc...HQ9bG93IGxldmVsIGZvcm1hdA**&p_li=&p_topview=1
Question
How can I low level format or erase a Western Digital hard
drive?
Answer
Western Digital provides software utilities that can erase all
the data on a hard drive. Writing zeros to a drive is recommended any
time an operating system is to be reinstalled on a boot drive or
whenever a blank drive is desired.
For more information on how to write zeros to your Western Digital
hard drive, please see the articles below.

Wdc.com has a support forum, I may post there but I wonder if I'll
learn anything I don't already know.
 
R

Rod Speed

I agree it would, it appears the sector marks and such are corrupted,

Maybe, or they're just marked as bad at the OS level by scandisk.
and nothing else will fix that.

You dont know that yet.
More googling didn't really find any "low-level
format" utility that will do these drives,

Yes, you cant do a true LLF on modern IDE drives.

They just ignore the LLF command and
write zeros thru all the sectors on the drive.
but it appears a lot of people are confused between
doing a "write zeroes" and a low-level format.

Yes, and that is because modern IDE drives just
write zeros thru all sectors when told to do a LLF.
What's worse is the Western Digital website adds to the confusion:

And quite a few other hard drive manufacturers do too,
deliberately using the term low level format for simplicity.
http://wdc.custhelp.com/cgi-bin/wdc...HQ9bG93IGxldmVsIGZvcm1hdA**&p_li=&p_topview=1
Question
How can I low level format or erase a Western Digital hard drive?
Answer
Western Digital provides software utilities that can erase
all the data on a hard drive. Writing zeros to a drive is
recommended any time an operating system is to be
reinstalled on a boot drive or whenever a blank drive is desired.
For more information on how to write zeros to your
Western Digital hard drive, please see the articles below.

WD does however have a ute that will rescan a drive for
new bad sectors and add them to the bad sector map.

That will likely fix whatever scandisk has done to the drive.

You need
http://support.wdc.com/download/index.asp?cxml=n&pid=999&swid=3
or
http://support.wdc.com/download/index.asp?cxml=n&pid=999&swid=30
 
F

Folkert Rienstra

Rod Speed said:
Yes they do.


Wrong. Those hard drive manufacturer's utes did that too.

Feel free to name one, (that isn't pre-IDE/ATA).
Separate issue entirely to what the hard drive manufacturer's utes do.

They do what the drive allows them to do and *that* isn't it.
There are no commands in ATA that allow that other than Format Track.
Its more complicated than that. As you know full well.

Bull. That's all there is to it.
 
F

Folkert Rienstra

Maybe, maybe not. S.M.A.R.T. should be able to tell.
Impossibly unlikely that that many would all go weak at once.

First, it aren't that many and second, if it was so bad what supposedly
has happened one would actually expect much much more gone bad.
What likely has happened is that the lesser areas, that were good enough
previously, have worsened under the influence of the monitor and now are
failing. Since data is rewritten and therefore should be as good as new it is
likely the Servo info or the Low Level Format detail, that *doesn't* get
rewritten, that's causing the misreads.
Its more complicated than that if what appears to be
bad varies due to that being due to external factors.

Read the post again.
On the first run he found many that then were taken out of service
as far as scandisk is concerned. Consecutive runs then found only a
few extra that weren't found the first time. Then he zeroed the drive
and scandisk checked all clusters again and found all the bad ones again.

That is to be expected *IF* the spots are weak (ie not really bad enough
to be replaced). If the spots are really bad they shouldn't reappear after
a 'zero' action unless the replacements are also bad (or weak), or the drive
is out of replacements.
 
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R

Ron Reaugh

list.

Yes they do.


Wrong. Those hard drive manufacturer's utes did that too.


Separate issue entirely to what the hard drive manufacturer's utes do.


Its more complicated than that. As you know full well.

Wacko speedo got it all wrong again.
 
R

Ron Reaugh

CWatters said:

Where it says:
"IDE hard drives can only be properly low-level formatted at the factory.
All IDE drives have control information on track 0 or -1 that only the
controller can read. This information includes bad track information, head
skew factors and zone sector information. Fortunately, all newer hard drives
only operate in a translation mode, so we can successfully do a format that
could be more properly called a mid-level format. I don't know of any virus
that can infect the low-level format installed by the manufacturer."

Can't low level format recent/current ATA HDs in the field.
 
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R

Ron Reaugh

Ben Bradley said:
That's one of several sites I found while researching this problem,
and that page doesn't seem to say much. The LLF programs they have are
very old and meant for older drives that had the capability of being
LLF'ed in the field. It appears that recent (in the last 10-15 years
or so) drives intentionally don't have that capability.

Right, can you say archaic.
 

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