Need some help from someone whod knows very well Quantum AS drives, please ...
I can't undrestand this :
Start with a clean secure erased and S.M.A.R.T. cleared HDD - Quantum AS.
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I attempt to do a read long command by C/H/S and get sector 1 with the ECC bytes at the end - 00 01 01 00 00 00 23
On a cleared drive all data is 00 and the 4 relevant byte of ECC is 00 while FF is ignored.
Now i write to the sector (edit buffer and send it to the drive with write long).
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So i'm going to write to the drive sector data but will maintain the same ECC (will write long with wrong ECC) instead of write and calculate new ECC. This will produce a BAD SECTOR :
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So far so good, now let's do a normal READ on the sector with wrong ECC :
As expected i get error and uncorrected :
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Now the "strange" thing, the drive puts the sector on the G-List and consider it as relocated and pending for relocation at the same time !!!
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I didn't attempt to write to the sector, i've just read it, and the drive placed it on G-List but for some reason the sector is on G-List and it's not swapped by a spare :
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Now it even gets more strange ..... If i WRITE back to the sector with correct data ....
Let's say i will clear the data on the buffer and write back to it :
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The sector disapear from G-List and Relocation Count on S.M.A.R.T. and pending Relocation as well !!!!!
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Note that I DIDN'T CLEAR S.M.A.R.T. neither cleared G-List !!!!
The fact that i was able to write back to the sector and the fact that it "disappeared" from G-List lead me to believe that the sector was NEVER swapped by a spare to start with, so why the hell was it on G-List ?
I was under the impression then when the drive relocates the sector by swaping with a spare only then the "bad" is placed on G-List ...
So how could this sector be on G-List and yet be accessable (original one and not the spare) and why did a "write" with correct ECC corrected the sector and removed it out of the G-List ?
Maybe this is how old drives got fixed with stuff like spinrite, if a "bad" sector or a sector without correct ECC gets read and the data is retrieved and written again, the ECC will be corrected and it looks like that at least on those old AS Quantum drives the "bad" sector is removed from G-List !!!!
This is really strange, because i was under the impression that when a sector was added to G-List unless one would use vendor specific commands to remove it from G-List or to clear G-List it would stay there for the rest of the life of the drive and the relocated sector would point out to a spare ...
Need help understanding this ....
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