They come in threes...

Bad things, that is.

After a long spell of being ignored my old home-built Windows Home Server
started to show a variety of odd problems. I used WD's diagnostics program
to check each of the 6 disks sequentially and finally came to drive #5
which showed stalling and slow progress in the sequential read test. That
lead me to digging through a stack of spare drives looking for a
replacement. That is when the first death occurred -- I accidentally
dropped a 3tB WD Green drive onto its corner on a hardwood floor; it tested
OK for a few minutes after the drop (whew!) but died immediately afterward
(damn!).

Back to the drive stack I dug out a 2tB Green that tested good but by then
I was unable to programmatically 'remove' the #5 drive from the storage
array and had to sacrifice all of my backups to swap the drive. So I
started to do some replacement backups only to find that progress was
impossible -- backup rate was so slow that it would take days to process
one machine. That lead me to run diagnostics on the sole untested drive in
the server -- it was defective too in the extended test.

Back to the drive stack to recover another 2tB drive. None there. Order one
from Amazon since they had gotten quite cheap lately. And when it arrived I
swapped it out after once again finding it impossible to 'remove' the bad
drive from the array. At that point I had a healthy server but one which
had no backups so I had to start that all over again.

I really can't fault WD on the drive failures. The 3tB I dropped certainly
wasn't their doing and the two 2tB drives that failed were quite old by
this time -- they were bought when that model drive had just been released
and had been running 24X7 ever since.

I think that from now on I'll maybe run a test on the server drives every
now and then and no ignore it for years on end...

John McGaw wrote:
Bad things, that is.

After a long spell of being ignored my old home-built Windows Home
Server started to show a variety of odd problems. I used WD's
diagnostics program to check each of the 6 disks sequentially and
finally came to drive #5 which showed stalling and slow progress in the
sequential read test. That lead me to digging through a stack of spare
drives looking for a replacement. That is when the first death occurred
-- I accidentally dropped a 3tB WD Green drive onto its corner on a
hardwood floor; it tested OK for a few minutes after the drop (whew!)
but died immediately afterward (damn!).

Back to the drive stack I dug out a 2tB Green that tested good but by
then I was unable to programmatically 'remove' the #5 drive from the
storage array and had to sacrifice all of my backups to swap the drive.
So I started to do some replacement backups only to find that progress
was impossible -- backup rate was so slow that it would take days to
process one machine. That lead me to run diagnostics on the sole
untested drive in the server -- it was defective too in the extended test.

Back to the drive stack to recover another 2tB drive. None there. Order
one from Amazon since they had gotten quite cheap lately. And when it
arrived I swapped it out after once again finding it impossible to
'remove' the bad drive from the array. At that point I had a healthy
server but one which had no backups so I had to start that all over again.

I really can't fault WD on the drive failures. The 3tB I dropped
certainly wasn't their doing and the two 2tB drives that failed were
quite old by this time -- they were bought when that model drive had
just been released and had been running 24X7 ever since.

I think that from now on I'll maybe run a test on the server drives
every now and then and no ignore it for years on end...

I recommend both "SMART" checking, as well as running a
transfer rate benchmark on each drive. (You might need
to move the drives to another machine, where they're not
considered to be part of a RAID, to do your block-level
verification.)

I ran into one case, where the slow read benchmark warned
that an excessive number of spared sectors were involved.
Whereas SMART showed "0" for Reallocated.

SMART works best for surveillance, if the spared sectors
are spaced uniformly over the disk. If a disk develops
a "bad spot", SMART may show a clean bill of health.
But a read transfer rate benchmark, might show 10MB
transfer rate for a 60GB patch on the disk, which is a
warning that the patch is "scruffy". And the drive
should be replaced immediately. There may be no CRC errors
in the patch, the data is still intact, but trouble for
you is right around the corner.

And drive failures can be instantaneous - the FDB spindle motor,
if it runs out of lubricant, can "seize" instantly, and no
longer rotate. Attempts to restart the drive, lead to the
"buzzing sound" they use to attempt to free up stuck
spindles. But that's not going to work, if the bearing
is dry. And apparently, the lubrication is only a
couple drops of oil. There is no "reservoir" as such.
No oil pan with 3 liters of oil.

To verify motor designs in the hard drive lab, they
weigh the motors on a milligram balance, to detect
when the two drops of oil have "disappeared". They don't
try to take the motor apart, and instead use "delta_weight"
to detect loss of lubricant. Weigh the motor before
starting a lifetime test, and weigh it again when it
seizes. That's how tiny the amount of lubricant is.

Paul

On 12/4/2015 1:19 PM, Paul wrote:
John McGaw wrote:
Bad things, that is.
snip...
I recommend both "SMART" checking, as well as running a
transfer rate benchmark on each drive. (You might need
to move the drives to another machine, where they're not
considered to be part of a RAID, to do your block-level
verification.)

I ran into one case, where the slow read benchmark warned
that an excessive number of spared sectors were involved.
Whereas SMART showed "0" for Reallocated.

SMART works best for surveillance, if the spared sectors
are spaced uniformly over the disk. If a disk develops
a "bad spot", SMART may show a clean bill of health.
But a read transfer rate benchmark, might show 10MB
transfer rate for a 60GB patch on the disk, which is a
warning that the patch is "scruffy". And the drive
should be replaced immediately. There may be no CRC errors
in the patch, the data is still intact, but trouble for
you is right around the corner.

And drive failures can be instantaneous - the FDB spindle motor,
if it runs out of lubricant, can "seize" instantly, and no
longer rotate. Attempts to restart the drive, lead to the
"buzzing sound" they use to attempt to free up stuck
spindles. But that's not going to work, if the bearing
is dry. And apparently, the lubrication is only a
couple drops of oil. There is no "reservoir" as such.
No oil pan with 3 liters of oil.

To verify motor designs in the hard drive lab, they
weigh the motors on a milligram balance, to detect
when the two drops of oil have "disappeared". They don't
try to take the motor apart, and instead use "delta_weight"
to detect loss of lubricant. Weigh the motor before
starting a lifetime test, and weigh it again when it
seizes. That's how tiny the amount of lubricant is.

Paul

The SMART results were totally useless in this case -- all six of the
drives, a 400gB and five 2tBs, showed that they were fine. At least that is
what the WD diagnostics showed in the SMART quick-test mode. It wasn't
until I did a long-form test that the stalling showed up. You know that you
are having trouble when the displayed estimated duration starts jumping up
instead of down and settles in the range of 2000 hours.

I'm certain that the motors didn't fail here although I guess it could have
been a speed problem of sort causing the stalling. Even the dropped 3tB
drive was certainly spinning up since when I checked it on the eSATA port
on my Shuttle it showed perfect gyroscopic behavior.

On 12/4/2015 12:05 PM, John McGaw wrote:
Bad things, that is.
snip...

I really can't fault WD on the drive failures. The 3tB I dropped certainly
wasn't their doing and the two 2tB drives that failed were quite old by
this time -- they were bought when that model drive had just been released
and had been running 24X7 ever since.

I think that from now on I'll maybe run a test on the server drives every
now and then and no ignore it for years on end...

On the road to destroying the drives for security I took the time to do
complete disassembly after I realized that I hadn't actually looked into
any modern drives.(and I wanted the magnets to play with) It was quite a
revelation: first off was the realization that one of the 2tB was an older
generation than I had imagined since it actually had four platters in it
while the slightly newer ones have only three. The 3tB also had four
platters and I believe that the full capacity of their newest drives is
around 1.25tB per platter or maybe more as I write. Second was the amazing
shrinkage of the heads; they are now down to a size that looks like a bit
of very fine wire sticking out of the ends of the drive arms. The fact that
heads so small can actually do anything and do it so quickly and accurately
is incredible to me.

Oh, and I have eight really really powerful magnets now although I haven't
figured out how to remove them from their metal mounting plates. Any ideas?

John McGaw wrote:
On 12/4/2015 12:05 PM, John McGaw wrote:
Bad things, that is.
snip...

I really can't fault WD on the drive failures. The 3tB I dropped
certainly
wasn't their doing and the two 2tB drives that failed were quite old by
this time -- they were bought when that model drive had just been
released
and had been running 24X7 ever since.

I think that from now on I'll maybe run a test on the server drives every
now and then and no ignore it for years on end...

On the road to destroying the drives for security I took the time to do
complete disassembly after I realized that I hadn't actually looked into
any modern drives.(and I wanted the magnets to play with) It was quite a
revelation: first off was the realization that one of the 2tB was an
older generation than I had imagined since it actually had four platters
in it while the slightly newer ones have only three. The 3tB also had
four platters and I believe that the full capacity of their newest
drives is around 1.25tB per platter or maybe more as I write. Second was
the amazing shrinkage of the heads; they are now down to a size that
looks like a bit of very fine wire sticking out of the ends of the drive
arms. The fact that heads so small can actually do anything and do it so
quickly and accurately is incredible to me.

Oh, and I have eight really really powerful magnets now although I
haven't figured out how to remove them from their metal mounting plates.
Any ideas?


In the two pictures here, it almost looks like some substance
was placed on the plate, to hold the magnet in a known position.

http://totallyunprepared.com/2013/03...stud-finder-2/

"The magnets in the hard drive were glued to the brackets. Although
the magnets look like they are made of steel, they are actually
somewhat delicate. We pulled them off using ViceGrip pliers because
that was the safe-for-people way to get them off. It risked damaging
the magnet; however trying to slip a screwdriver under the magnet
to pry it off is the you-are-probably-going-to-slip-and-hurt-yourself
way, so, um, don’t do that."

AFAIK, the magnets are positioned in an "attracting
each other" orientation.

N ---------- S

S ---------- N

So a means is needed to keep them from
slamming together and pinching the voice coil.

Paul

On 12/11/2015 2:32 PM, Paul wrote:
John McGaw wrote:
On 12/4/2015 12:05 PM, John McGaw wrote:
Bad things, that is.
snip...

I really can't fault WD on the drive failures. The 3tB I dropped certainly
wasn't their doing and the two 2tB drives that failed were quite old by
this time -- they were bought when that model drive had just been released
and had been running 24X7 ever since.

I think that from now on I'll maybe run a test on the server drives every
now and then and no ignore it for years on end...

On the road to destroying the drives for security I took the time to do
complete disassembly after I realized that I hadn't actually looked into
any modern drives.(and I wanted the magnets to play with) It was quite a
revelation: first off was the realization that one of the 2tB was an
older generation than I had imagined since it actually had four platters
in it while the slightly newer ones have only three. The 3tB also had
four platters and I believe that the full capacity of their newest drives
is around 1.25tB per platter or maybe more as I write. Second was the
amazing shrinkage of the heads; they are now down to a size that looks
like a bit of very fine wire sticking out of the ends of the drive arms.
The fact that heads so small can actually do anything and do it so
quickly and accurately is incredible to me.

Oh, and I have eight really really powerful magnets now although I
haven't figured out how to remove them from their metal mounting plates.
Any ideas?


In the two pictures here, it almost looks like some substance
was placed on the plate, to hold the magnet in a known position.

http://totallyunprepared.com/2013/03...stud-finder-2/

"The magnets in the hard drive were glued to the brackets. Although
the magnets look like they are made of steel, they are actually
somewhat delicate. We pulled them off using ViceGrip pliers because
that was the safe-for-people way to get them off. It risked damaging
the magnet; however trying to slip a screwdriver under the magnet
to pry it off is the you-are-probably-going-to-slip-and-hurt-yourself
way, so, um, don’t do that."

AFAIK, the magnets are positioned in an "attracting
each other" orientation.

N ---------- S

S ---------- N

So a means is needed to keep them from
slamming together and pinching the voice coil.

Paul

I think that I'm going to get out my 1" carpentry (as opposed to
woodworking) chisel and try to separate a magnet that way. If there is glue
(and I'm pretty sure that there must be) a bit of inclined-plane action
might have a chance of getting it off intact. I've got eight to play with
so there isn't much to lose. These magnets see to be way more powerful than
those I salvaged in the old days and I was toying with the idea of "the
world's strongest refrigerator magnet" using two of the magnets in a
sculpted exotic wood block and capable of holding up a ream of paper. Well,
maybe not a ream but perhaps a cm?

On 12/11/2015 3:04 PM, John McGaw wrote:
On 12/11/2015 2:32 PM, Paul wrote:
John McGaw wrote:
On 12/4/2015 12:05 PM, John McGaw wrote:
Bad things, that is.
snip...

I really can't fault WD on the drive failures. The 3tB I dropped certainly
wasn't their doing and the two 2tB drives that failed were quite old by
this time -- they were bought when that model drive had just been released
and had been running 24X7 ever since.

I think that from now on I'll maybe run a test on the server drives every
now and then and no ignore it for years on end...

On the road to destroying the drives for security I took the time to do
complete disassembly after I realized that I hadn't actually looked into
any modern drives.(and I wanted the magnets to play with) It was quite a
revelation: first off was the realization that one of the 2tB was an
older generation than I had imagined since it actually had four platters
in it while the slightly newer ones have only three. The 3tB also had
four platters and I believe that the full capacity of their newest drives
is around 1.25tB per platter or maybe more as I write. Second was the
amazing shrinkage of the heads; they are now down to a size that looks
like a bit of very fine wire sticking out of the ends of the drive arms.
The fact that heads so small can actually do anything and do it so
quickly and accurately is incredible to me.

Oh, and I have eight really really powerful magnets now although I
haven't figured out how to remove them from their metal mounting plates.
Any ideas?


In the two pictures here, it almost looks like some substance
was placed on the plate, to hold the magnet in a known position.

http://totallyunprepared.com/2013/03...stud-finder-2/

"The magnets in the hard drive were glued to the brackets. Although
the magnets look like they are made of steel, they are actually
somewhat delicate. We pulled them off using ViceGrip pliers because
that was the safe-for-people way to get them off. It risked damaging
the magnet; however trying to slip a screwdriver under the magnet
to pry it off is the you-are-probably-going-to-slip-and-hurt-yourself
way, so, um, don’t do that."

AFAIK, the magnets are positioned in an "attracting
each other" orientation.

N ---------- S

S ---------- N

So a means is needed to keep them from
slamming together and pinching the voice coil.

Paul

I think that I'm going to get out my 1" carpentry (as opposed to
woodworking) chisel and try to separate a magnet that way. If there is glue
(and I'm pretty sure that there must be) a bit of inclined-plane action
might have a chance of getting it off intact. I've got eight to play with
so there isn't much to lose. These magnets see to be way more powerful than
those I salvaged in the old days and I was toying with the idea of "the
world's strongest refrigerator magnet" using two of the magnets in a
sculpted exotic wood block and capable of holding up a ream of paper. Well,
maybe not a ream but perhaps a cm?

I verified that a sharp chisel works a treat in removing the magnets from
their plates but the adhesive that was used is so tenacious that it pulls
the shiny plating from the back of the magnet and leaves it on the plate.
This is probably not good for the long-term life of the magnets but I'll
continue with it since I don't have any clue about a better way. The
magnets are damned strong and when they stick to the chisel they are
impossible to pull off and must be slid off the edge.