DVD burner vanished

  • Thread starter Thread starter Linea Recta
  • Start date Start date
Char said:
I'm surprised to learn that the OS knows or cares about such low level
details. I had expected the IDE interface to hide (abstract) all of
that from the OS.

There are various tables around. Example here.

http://www.wdc.com/global/products/features/?id=7&language=1

They really don't need to do that for smaller drives.
It's totally unnecessary. Which is why I'm unhappy to see
500GB drives that way. My 250GB drives were the last smooth
ones I owned.

Paul
 
There are various tables around. Example here.

http://www.wdc.com/global/products/features/?id=7&language=1

They really don't need to do that for smaller drives.
It's totally unnecessary. Which is why I'm unhappy to see
500GB drives that way. My 250GB drives were the last smooth
ones I owned.

Thanks, but I really didn't see anything there that talked about the
OS being aware of the hard drive's formatted sector size during
routine read/write operations. That's ok, though. I was only mildly
curious.
 
Paul said:
Enjoy your 512 byte physical/512 byte logical drive :-)

That's the "old fashioned" type.

I have about four 500GB drives here, SATA drives. I suspect,
based on behavior, they all have 4K sectors underneath.

You're not sure? How can one verify this? I have a 500 GB drive too, but
this is an external USB drive. I believe there is a seagate inside because
model ID is ST3500820AS. I see here in HD Sentinel: Bytes Per Sector, 512
(amonst a load of other data).

Although one of them claims to be 512 byte physical/ 512 byte logical,
it has the same crappy behavior as the latest drives I got.
(Doesn't run "smooth" as it should. Transfer rate is like
"waves of the ocean". Up n' down until you're seasick.)

Do you ever defragment? Because of moving the pagefile yesterday, I even
defragmented the page file with the utility of Russinovich.

The latest drives are 4096 byte physical/512 byte logical,
otherwise known as "512e" or 512 byte emulated drives. Seagate
does read/modify/write operations, so at the user level, it
still looks like a 512 byte sector that an older OS can use. But
such a scheme exacts a performance penalty.

Western Digital, I think they make 4096 physical/4096 logical,
which works seamless on Windows 7 with patch, but needs
"alignment" elsewhere.

I've been experimenting the last few days, trying to get the
4096/512 drive to behave better. And so far I haven't succeeded.
I crudely aligned a FAT32 partition, using a change to reserved
sector count, and that didn't do squat for me. Much to my surprise.


I only have some USB-sticks formatted FAT32. All harddisks are formatted
NTFS. And another thing: I dont like dividing up my disks in smaller
partitions. I think this is countereffective as regards to use of space,
specially if you want to manage the partitions with a partition manager,
which itself takes even more of your space.

I'm left to conclude, that the cache handling inside the hard
drive, is about as effective as SMARTDRV from DOS days - it
needs to dump the cache at regular intervals, causing a several
second delay until more files can be handled.

I haven't cracked the performance puzzle yet.

The fact you've got a 512/512 drive, is something to be happy about.
I'd be doing a happy dance around the computer right now, if

Afraid I havn't had dancing lessons...

that's what I had in front of me. Mainly because I could just
use it, and no more experiments would be required.

Paragon makes an alignment utility, but they want $30 for it.
My problem with that, is I'm particular about who I give
my credit card details to. And I won't be dealing direct with

I never had, nor ever will have a credit card. Most web shops in Netherlands
can also be paid (free!) through 'Ideal'.

Paragon, because they're in Germany as far as I know. The last
time I tried to buy software from Germany, my card was declined,
and I got a phone call later from the credit card company. That
kinda takes the fun out of it. At the time that happened,
I actually ended up getting double billed, and it took forever
to resolve. So I'd just like to buy from someone who
uses a North American credit card processor.

I understand, that's lousy luck...


Now for another little problem: privacy. I tried to open up the broken
drives yesterday, in an attempt to phisically damage the plates with a
screwdriver. One of them couldn't be opened because the screws had
triangular holes in stead of Philips cross. The next best thing I could
think of was to drop the drives from 2 metres heigh on a concrete floor. I
assume this rendered them useless before putting them in the waste bin...



--
regards,

|\ /|
| \/ |@rk
\../
\/os
 
Linea said:
You're not sure? How can one verify this? I have a 500 GB drive too, but
this is an external USB drive. I believe there is a seagate inside because
model ID is ST3500820AS. I see here in HD Sentinel: Bytes Per Sector, 512
(amonst a load of other data).

When I say that, what I mean is, the drive is probably using a 4K sector
internally, but the *electronic* identification of the drive claims it
is a 512/512 drive. The addition of proper identification, was some
addition of information to the ATA spec. Later drives, properly
report size. Since I'm still working on this as a "project" for myself,
here's the latest link I found with some discussion.

http://www.johannes-bauer.com/linux/wdc/?menuid=3

As for a utility, this is one I tried yesterday.

http://downloads.dell.com/FOLDER96706M/22/DELL_ADVANCED-FORMAT-HDD-DET_A00_R306204.exe

Inside there, is a file "DellAFDT.exe" which I extracted with 7ZIP.
It runs from the command prompt. Here is the output from my
(suspected dishonest) drive and my latest 4K drive. The 4K drive,
since it is more honestly reporting logical and physical characteristics,
the Dell utility reports it is not aligned properly. (If you were running
this in Windows 7, you might want to use a "Run as Administrator" cmd.exe window,
as I suspect the access of low level hardware details might need it.)

The first drive is 500GB, but behaves a bit choppy. Choppy behavior
can be caused by lots of spared-out sectors. So that is still a possibility.
Since all the identify words are zero, I expect the drive just isn't designed
to report anything for the appropriate parameters. And since the Dell utility
has checked the params, and found them to indicate 512/512 byte per sector
drive, all partitions are claimed to be aligned. (Because partitions on "old"
drives, don't have an alignment issue.) But my suspicion is, this is a
512e drive (4096 physical 512 logical) and not really a true
old fashioned 512 byte drive.

Model: ST3500418AS
Serial#: 9VMXTKA9
Advanced Format: No
Partition Alignment: Aligned
Partition 1: Aligned [G:]
Partition 2: Aligned [M:]
Partition 3: Aligned [Not assigned]
Partition 4: Aligned [N:]
Identify Data Word 106: 0x0
Identify Data Word 117: 0x0
Identify Data Word 118: 0x0
Identify Data Word 209: 0x0

This is my latest purchased drive. In Linux, this reports as 4096 physical
and 512 logical type drive. The Dell utility can easily tell that my CHS
prepared disk (partitioned in WinXP) is mis-aligned. But because the drive
emulated 512 byte sector operations (you write 512 bytes and it doesn't care),
this is all handled for you. It's just, if the partitions were better aligned,
then the cache behavior used to hide the details, would no longer be necessary.
But the cache is always running anyway, so the overhead involved (cache
management policy inside the drive) is still going to be there.

Model: ST500DM002-1BD142
Serial#: W2A95XHC
Advanced Format: Yes
Logical sectors per physical sector: 8
Logical sector size (in bytes): 512
Partition Alignment: Misaligned
Partition 1: Misaligned [C:]
Partition 2: Misaligned [D:]
Partition 3: Misaligned [E:]
Partition 4: Misaligned [W:]
Identify Data Word 106: 0x6003
Identify Data Word 117: 0x0
Identify Data Word 118: 0x0
Identify Data Word 209: 0x4000

What I don't know, and what I've been researching as hard as I can, is
whether *any* utility understands FAT32 well enough, to understand that
aligning the front of the entire partition is one thing, but aligning
the clusters inside is a separate issue. The two FATs in FAT32, take
variable storage area, which causes the clusters to start where ever they
fall. Some nice pictures here, if needed...

http://www.pjrc.com/tech/8051/ide/fat32.html

http://www.pjrc.com/tech/8051/ide/fat32_layout.gif

As you change the overall size of the partition, the size of the FATs
change at the same time. If you change from 16K clusters to 32K clusters,
the size of the fat changes by a factor of two as well. It takes four
bytes of storage in a FAT, to store a link to a cluster. Which is how
that space is determined. If you radically change the number of clusters,
the FATs also change in size (as the number of 4 byte pointers to store
has changed).

I'm also going to need to research this for NTFS, but haven't got there
yet. First, I need to understand how to fix the FAT32. And whether the
purchase of the Paragon tool, would actually ensure the clusters are
aligned to 4K or not. When I did this manually from Linux (backup and
restore, using mkfs.vfat command to custom set up FAT32 partition),
it didn't seem to make a performance difference. And when I ran
"fixboot C:" from the WinXP installer CD later, that's when the
partition boot sector was put in the wrong place, and I couldn't
boot from that FAT32 partition. I was able to test the partition,
for write performance, but when finished, it wouldn't boot. Which
means I have more work to do. I'd probably need to leave the
Reserved Sectors field at the normal 32 value, and just resize the
partition a bit, to adjust the size of the FATs where they need to be.

This is what I tried in Linux, to make a fresh partition to
test with. 64 --> 32768 byte cluster. The R parameter is reserved
sectors at the front of the partition, and I changed that from the
normal 32 to 39 for my test. Using a hex editor, I checked the first
file on the new partition, and it was 4K aligned (32K cluster aligned
with 4K boundary). But when I did fixboot C: from WinXP, it seemed to
put the partition boot sector in the wrong place. So maybe it doesn't
like "R 39".

mkfs.vfat -a -F 32 -n WINXP -v -s 64 -R 39 /dev/sdc1

Paul
 
Now for another little problem: privacy. I tried to open up the broken
drives yesterday, in an attempt to phisically damage the plates with a
screwdriver. One of them couldn't be opened because the screws had
triangular holes in stead of Philips cross. The next best thing I could
think of was to drop the drives from 2 metres heigh on a concrete floor. I
assume this rendered them useless before putting them in the waste bin...

You might be surprised at how ineffective dropping can be, at least
with regards to the platters.

When I was in the military, we had a large-ish machine that looked
like a paper shredder on steroids. You could drop a hard drive into it
and it would spit out fingernail-sized pieces of metal. We mostly used
it to grind up classified documents, up to about 4 inches thick.
Before we got that machine, we would destroy hard drives with a
5-pound sledge hammer.
 
Char Jackson said:
You might be surprised at how ineffective dropping can be, at least
with regards to the platters.

When I was in the military, we had a large-ish machine that looked
like a paper shredder on steroids. You could drop a hard drive into it
and it would spit out fingernail-sized pieces of metal. We mostly used
it to grind up classified documents, up to about 4 inches thick.
Before we got that machine, we would destroy hard drives with a
5-pound sledge hammer.



You may be right, but I think I'm not allowed to use a sledge hammer in my
apartment :-)
One thing is sure though. When trying to destroy an old drive, chances are
considerable that it can still be read. On the other hand, when a new drive
is dropped
by accident, you can be sure it is dead. I suppose this is what they call
paranoia...



--
regards,

|\ /|
| \/ |@rk
\../
\/os
 
Paul said:
Linea said:
You're not sure? How can one verify this? I have a 500 GB drive too, but
this is an external USB drive. I believe there is a seagate inside
because model ID is ST3500820AS. I see here in HD Sentinel: Bytes Per
Sector, 512 (amonst a load of other data).

When I say that, what I mean is, the drive is probably using a 4K sector
internally, but the *electronic* identification of the drive claims it
is a 512/512 drive. The addition of proper identification, was some
addition of information to the ATA spec. Later drives, properly
report size. Since I'm still working on this as a "project" for myself,
here's the latest link I found with some discussion.

http://www.johannes-bauer.com/linux/wdc/?menuid=3

As for a utility, this is one I tried yesterday.

http://downloads.dell.com/FOLDER96706M/22/DELL_ADVANCED-FORMAT-HDD-DET_A00_R306204.exe

Inside there, is a file "DellAFDT.exe" which I extracted with 7ZIP.
It runs from the command prompt. Here is the output from my
(suspected dishonest) drive and my latest 4K drive. The 4K drive,
since it is more honestly reporting logical and physical characteristics,
the Dell utility reports it is not aligned properly. (If you were running
this in Windows 7, you might want to use a "Run as Administrator" cmd.exe
window,
as I suspect the access of low level hardware details might need it.)

The first drive is 500GB, but behaves a bit choppy. Choppy behavior
can be caused by lots of spared-out sectors. So that is still a
possibility.
Since all the identify words are zero, I expect the drive just isn't
designed
to report anything for the appropriate parameters. And since the Dell
utility
has checked the params, and found them to indicate 512/512 byte per sector
drive, all partitions are claimed to be aligned. (Because partitions on
"old"
drives, don't have an alignment issue.) But my suspicion is, this is a
512e drive (4096 physical 512 logical) and not really a true
old fashioned 512 byte drive.

Model: ST3500418AS
Serial#: 9VMXTKA9
Advanced Format: No
Partition Alignment: Aligned
Partition 1: Aligned [G:]
Partition 2: Aligned [M:]
Partition 3: Aligned [Not assigned]
Partition 4: Aligned [N:]
Identify Data Word 106: 0x0
Identify Data Word 117: 0x0
Identify Data Word 118: 0x0
Identify Data Word 209: 0x0

This is my latest purchased drive. In Linux, this reports as 4096 physical
and 512 logical type drive. The Dell utility can easily tell that my CHS
prepared disk (partitioned in WinXP) is mis-aligned. But because the drive
emulated 512 byte sector operations (you write 512 bytes and it doesn't
care),
this is all handled for you. It's just, if the partitions were better
aligned,
then the cache behavior used to hide the details, would no longer be
necessary.
But the cache is always running anyway, so the overhead involved (cache
management policy inside the drive) is still going to be there.

Model: ST500DM002-1BD142
Serial#: W2A95XHC
Advanced Format: Yes
Logical sectors per physical sector: 8
Logical sector size (in bytes): 512
Partition Alignment: Misaligned
Partition 1: Misaligned [C:]
Partition 2: Misaligned [D:]
Partition 3: Misaligned [E:]
Partition 4: Misaligned [W:]
Identify Data Word 106: 0x6003
Identify Data Word 117: 0x0
Identify Data Word 118: 0x0
Identify Data Word 209: 0x4000

What I don't know, and what I've been researching as hard as I can, is
whether *any* utility understands FAT32 well enough, to understand that
aligning the front of the entire partition is one thing, but aligning
the clusters inside is a separate issue. The two FATs in FAT32, take
variable storage area, which causes the clusters to start where ever they
fall. Some nice pictures here, if needed...

http://www.pjrc.com/tech/8051/ide/fat32.html

http://www.pjrc.com/tech/8051/ide/fat32_layout.gif

As you change the overall size of the partition, the size of the FATs
change at the same time. If you change from 16K clusters to 32K clusters,
the size of the fat changes by a factor of two as well. It takes four
bytes of storage in a FAT, to store a link to a cluster. Which is how
that space is determined. If you radically change the number of clusters,
the FATs also change in size (as the number of 4 byte pointers to store
has changed).

I'm also going to need to research this for NTFS, but haven't got there
yet. First, I need to understand how to fix the FAT32. And whether the
purchase of the Paragon tool, would actually ensure the clusters are
aligned to 4K or not. When I did this manually from Linux (backup and
restore, using mkfs.vfat command to custom set up FAT32 partition),
it didn't seem to make a performance difference. And when I ran
"fixboot C:" from the WinXP installer CD later, that's when the
partition boot sector was put in the wrong place, and I couldn't
boot from that FAT32 partition. I was able to test the partition,
for write performance, but when finished, it wouldn't boot. Which
means I have more work to do. I'd probably need to leave the
Reserved Sectors field at the normal 32 value, and just resize the
partition a bit, to adjust the size of the FATs where they need to be.

This is what I tried in Linux, to make a fresh partition to
test with. 64 --> 32768 byte cluster. The R parameter is reserved
sectors at the front of the partition, and I changed that from the
normal 32 to 39 for my test. Using a hex editor, I checked the first
file on the new partition, and it was 4K aligned (32K cluster aligned
with 4K boundary). But when I did fixboot C: from WinXP, it seemed to
put the partition boot sector in the wrong place. So maybe it doesn't
like "R 39".

mkfs.vfat -a -F 32 -n WINXP -v -s 64 -R 39 /dev/sdc1


Thanks very much for your detailed replies.



--
regards,

|\ /|
| \/ |@rk
\../
\/os
 
Paragon makes an alignment utility, but they want $30 for it.
My problem with that, is I'm particular about who I give
my credit card details to. And I won't be dealing direct with
Paragon, because they're in Germany as far as I know. The last
time I tried to buy software from Germany, my card was declined,
and I got a phone call later from the credit card company. That
kinda takes the fun out of it. At the time that happened,
I actually ended up getting double billed, and it took forever
to resolve.

That's why "one" (ME), never buys software unless it can be paid for using
PayPal !!!!
i.e. the software vendor never gets to see "ones" CC details, i.e. PayPal is
the intermediary - PayPal hands "ones" money to the software vendor etc.
etc.
....and unless one has been stupid enough to allow https sniffing software
into ones PC, one is reasonably secure !!!!

"one" has to admit that a couple of years ago, I paid for petrol at a
service station in Bridgewater, (a service station that I'd never used
before), and when my CC card was inserted into the CC machine, (my 6th sense
instantly was ringing a 110 decibel alarm during the transaction - which I
STUPIDLY ignored), i.e. I felt unexplainably uneasy as the "moustached and
heavily tanned" cashier, ....served me !!

With hindsight, .....I strongly suspect that his "moustached & heavily
tanned" colleagues were crouched over computer hardware on the floor above
that filling stations' cashier counter, ....gathering card details and
firing them abroad to the USA !!!!!!!!!!!!!!!

A couple of days later I recieved an automated fraud alert from my bank,
advising me that two transactions had been attempted in a State, in the USA,
one at a computer store for just a few UK pounds, and one at a bus/coach
station - for just a few UK pounds, both were automatically declined by my
bank, that had detected that I could not be in two places at once !!!!!
I was told by my bank that that those were most likely two "test"
transactions and that if they had gone through, I would have been hit HARD
!!!!!!!

....so there you are, my advice is only buy software if PayPal is a payment
option :-)
....never use ones CC at an unknown BP ooops !!! filling station, or any
other unfamiliar establishment where one could use CASH !!

regards, Richard
 
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