By LLF I mean marking bad sectors in the primary defect table of a drive.
Can the LLF Tool do that for the supported drive brands?

Thank you,
/_urka

I dont know witch one LLF tool you mentioned, but in general all "LLF" tools just fills the drive with zeros, and has nothing to do with defect table. There is no such thing in modern drive like LowLevelFormat.

How is it done in factory? Is a special controller required?

Bye,
/_urka

Hi,

yes, they use servo writer to write low-level information.

pepe

Hi pepe,
what you have in mind when you said write low-level information?
IMHO any tool that can operate with factory defect list is low level format tool. Since it hide defects and this way change the translator...

_________________
DataRecovery.bg

Hi,

When U format a floppy disk, the drive writes all the neccessary info (address marks, ID fields, sector space initialized) to the disk. In other words it creates the format it can read afterwards.
U cannot do this with a modern hard drive, if the servo info and other metadata that helps the FW find a sector is lost, the drive is in big trouble, since it cannot even stabilize the position of the heads.
In a floppy drive this is not a problem since it has stepper motor mechanism and much wider tolerance in positions.
In a the HDD there is no stepper motor, so the head positioning relies uppon the servo information. That's why it cannot be low level formatted, since to write this information the drive needs its heads to be positioned externally by the servo writer (since there is no servo yet), and this is accomplished through an opening on the case that is covered after servo writing by a sticker usually.

regards,
pepe

Hi,
The servowriter mark only the servo points. I.e the borders between physical cyls. All other like address marks, ID fields is done by selftest.

_________________
DataRecovery.bg

OK,

But changing the defect list (translator) does not rewrite address marks and ID fields we have to agree in that.


pepe

OK,
but if you add defect in factory list then it is added as CHS. The physical ID is not chaged, is just skipped, but the LBA IDs are shifted and the translator is changed, unlike adding defects to user list where the defect LBA is just substituted. Thats what i mean.

_________________
DataRecovery.bg

Hi,

Yes, that's true. But an LLF tool should re-initialize all these metadata fields so that sectors that could not be found before have good address marks and IDs after the LLF. There is no such tool for modern HDDs, this is what i mean. BTW I am not sure wether selfscan procedure does this, I have never used it (for DR it is not needed).
pepe

I agree, but what happen if those tool can't re-initialize the data in case of physical damage(scratch, local damage ...) not now, but in the past when LLF exist? They were excluded, right? And was written in a table on the top cover with pencil, or inside in table.

As an example you can take N40P and see the physical cyls in 20 and 40GB. All they are servo marked as 40GB but the microprogram can be set to control(cut or increase) the capacity at least in 3 different ways.

_________________
DataRecovery.bg

Hi,


as far as this model is concerned, the final size depends on the quality of the platter. U are right, they are formatted the same number of tracks and the same SPT each model. And bad cyls are skipped by the translator and the max LBA is reduced.
I had a very bad case with a 2F030 drive that someone overwrote the SA before it came to me. I received a backup of the modules, but they were full of errors, so I could hardly use anything.
The data area had many tracks that were mapped out, therefore it was very hard to recover the translator.
Anyway, this drive was made 30GB because of the bad quality of the platter.
regards,
pepe