Is a HDD still functional after using Secure Erase?

J

Jon Danniken

Hi guys, this is kind of a weird question, but I am purchasing a used hard
drive and plan on using Secure Erase
(http://cmrr.ucsd.edu/people/Hughes/SecureErase.shtml) on it before I format
it and install Windows on it. The application, "Secure Erase", uses the ATA
internal command that is built into the hard drive itself (as you probably
already know).

My concern is that the drive will be wiped so well that it will lose the
ability to be partitioned and formatted. I'm guessing that my concern is
not valid, but I should have a more definitive answer before I make an
expensive paperweight that looks like a hard drive.


Thanks,

Jon
 
M

Massimo

Hi guys, this is kind of a weird question, but I am purchasing a used hard
drive and plan on using Secure Erase
(http://cmrr.ucsd.edu/people/Hughes/SecureErase.shtml) on it before I format
it and install Windows on it. The application, "Secure Erase", uses the ATA
internal command that is built into the hard drive itself (as you probably
already know).

My concern is that the drive will be wiped so well that it will lose the
ability to be partitioned and formatted. I'm guessing that my concern is
not valid, but I should have a more definitive answer before I make an
expensive paperweight that looks like a hard drive.


Thanks,

Jon
What do you think yourself?! If a secure erase could be deadly for a
ssd then nobody would use the program. And a secure erase before
reusing a ssd is even advised by several people...

Massimo
 
P

Paul

Jon said:
Hi guys, this is kind of a weird question, but I am purchasing a used hard
drive and plan on using Secure Erase
(http://cmrr.ucsd.edu/people/Hughes/SecureErase.shtml) on it before I format
it and install Windows on it. The application, "Secure Erase", uses the ATA
internal command that is built into the hard drive itself (as you probably
already know).

My concern is that the drive will be wiped so well that it will lose the
ability to be partitioned and formatted. I'm guessing that my concern is
not valid, but I should have a more definitive answer before I make an
expensive paperweight that looks like a hard drive.


Thanks,

Jon

I Secure Erased a drive, and am still using it.

Be aware, that at least one computer design out there, cannot
tolerate an "all zeros" drive. I have a computer here, that
stalls in the BIOS, if a zeroed drive is connected. To escape,
I have to connect the drive to another computer, then use
disk management to put one partition on it. And then, the
BIOS on the other computer doesn't mind if the drive is
re-connected. So that tells me, the BIOS snoops the content of
the hard drive (the first sector) a little too much for its
own good. In that case, the BIOS would just sit there, even
though the BIOS settings are not set to try to boot from that
drive. There could be a perfectly valid boot drive, plus a
second "all zeros" hard drive, and then the BIOS just
sits there, and nothing happens.

Paul
 
J

Jon Danniken

Paul said:
I Secure Erased a drive, and am still using it.

Be aware, that at least one computer design out there, cannot
tolerate an "all zeros" drive. I have a computer here, that
stalls in the BIOS, if a zeroed drive is connected. To escape,
I have to connect the drive to another computer, then use
disk management to put one partition on it. And then, the
BIOS on the other computer doesn't mind if the drive is
re-connected. So that tells me, the BIOS snoops the content of
the hard drive (the first sector) a little too much for its
own good. In that case, the BIOS would just sit there, even
though the BIOS settings are not set to try to boot from that
drive. There could be a perfectly valid boot drive, plus a
second "all zeros" hard drive, and then the BIOS just
sits there, and nothing happens.

Thanks Paul, I appreciate it. One other thing I think I read about is that
SE also removes sectors marked as bad, but now I can't find the page (of
course). Fortunately the drive I'm buying only has 90 hours on it, so maybe
I'll be fine.

Jon
 
P

Paul

Jon said:
Thanks Paul, I appreciate it. One other thing I think I read about is that
SE also removes sectors marked as bad, but now I can't find the page (of
course). Fortunately the drive I'm buying only has 90 hours on it, so maybe
I'll be fine.

Jon

Yeah, I read that somewhere too, that the spare sectors also get erased.
What that means is, the head will pass over all sectors, and apply
write current. But it doesn't have to verify how the write turned out.
It's not a write-verify kind of operation, more or less a "best effort",
since it's inevitable that some sectors are too defective to be touched
(like, embedded sync is missing as well). If the embedded sync is
demagnetized, then the head won't be able to actively track position
and keep the head over the track. The erase routine would have to move
on to the next location, if that happens.

Paul
 
J

Jon Danniken

Paul said:
Yeah, I read that somewhere too, that the spare sectors also get
erased. What that means is, the head will pass over all sectors, and
apply write current. But it doesn't have to verify how the write
turned out. It's not a write-verify kind of operation, more or less a
"best effort", since it's inevitable that some sectors are too
defective to be touched (like, embedded sync is missing as well). If
the embedded sync is demagnetized, then the head won't be able to
actively track position and keep the head over the track. The erase
routine would have to move on to the next location, if that happens.

Paul

I think my concern is that whatever effort the drive has put into
identifying bad sectors is going to be wiped over, re-exposing the bad
sectors as legitimate locations, instead of as marked bad. In other words,
does the record that identifies bad sectors get written over as well?

Jon
 
P

Paul

Jon said:
I think my concern is that whatever effort the drive has put into
identifying bad sectors is going to be wiped over, re-exposing the bad
sectors as legitimate locations, instead of as marked bad. In other words,
does the record that identifies bad sectors get written over as well?

Jon

No, the state of automatic sector sparing should be preserved.
The "bad" sectors are still bad, and their replacements are still in usage.

It would go against the ATA/ATAPI sense of automatic sector sparing,
to unto that. But SCSI heritage drives support that kind of thing - the
ability for the user to override the system (I've done it, to drives at
work). AFAIK, ATA/ATAPI doesn't have that as an option. ATA/ATAPI drives
have private means to make changes to drive state - one would be some kind
of factory software, or perhaps by means of a firmware update. The drives
accept firmware updates, either temporary ones, or permanent ones. And some
drives have a three pin serial port interface, and there is some kind of
terse language used there to talk to the controller. Perhaps some command
there could do it. But using regular protocol commands over IDE ribbon or SATA cable,
probably not. The ATA/ATAPI automatic system continues to maintain the same state.

Paul
 

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