Formatting a HD to extend its life?

[imagoon]

you got it confused.

although the practice is not done much anymore, there are still available utilities to low level format (try google) - should the situation deem necessary - such as this case in this thread.

as with a new drive purchase. there is a level of trust toward a manufacturer. hence no need for low level format. as with a used drive purchase. you definitely want to low level before putting your precious data on it. some of us will low level format a new drive just for our personal peace of mind.

low level format is basically zero-ing out the drive. while the platter is being zero out, it also gets checked in the process. a bad spot will not zero out and is marked bad.

once the drive get zero out. the next step is partition setup.

after that. then the high level format (aka quick format). which is the allocation table (FAT/FAT32/NTFS/etc).

now the drive is ready for data. all new data written will have a fresh magnetic signal.

No. True low level formatting puts the drive tracking and sector positioning data on the drive. In order to do this on any modern drive, you would need the head alignment / magnetic tracking system at the factory to lay down the cylinder tracking patterns. There is a sticker covered hole near the head servo assembly where these machines connect and externally position the heads and has the heads write the pattern.

Zeroing out a drive is not a low level format, it is just Zeroing. The check is just disk checking. You can do destructive testing if you want where you write and read back test patterns.

There is no way in the field to rewrite the positional data on the drive. It used to be that one side of a platter was reserved for this and the write head was disabled after alignment. This may or may not still be true. It was the main reason why 2 platters were needed for 2TB drives using 1TB platters etc.

 

[Russwinters]

Drives use embedded servo nowadays (weaved throughout all of the platters in between the user tracks/sectors), also only WD and samsung (well, samsung HDD division was bought out by seagate)

only those two manufacturers still use the type of servo writing you mentioned anymore.

Other manufacturer can write servo with the installed R/W heads, firmware has a special mode in which heads will write servo, and it can be re-run if you can reverse engineer the manufacturers specific commands, but its pretty useless as the amount of work involved is too much considering rewriting servo will make user data gone, so you wouldn't use this for Data recovery or forensics which is the only thing that would pay enough to make you want to do this anyways.

 

[imagoon]

Drives use embedded servo nowadays (weaved throughout all of the platters in between the user tracks/sectors), also only WD and samsung (well, samsung HDD division was bought out by seagate)

only those two manufacturers still use the type of servo writing you mentioned anymore.

Other manufacturer can write servo with the installed R/W heads, firmware has a special mode in which heads will write servo, and it can be re-run if you can reverse engineer the manufacturers specific commands, but its pretty useless as the amount of work involved is too much considering rewriting servo will make user data gone, so you wouldn't use this for Data recovery or forensics which is the only thing that would pay enough to make you want to do this anyways.

Do you have a link? I want to update myself.

PS for those wondering what I was babbling about:

http://www.google.com/patents?id=IRcSAAAAEBAJ&printsec=abstract&zoom=4#v=onepage&q&f=false

 

[Russwinters]

http://hddscan.com/doc/HDD_Tracks_and_Zones.html


article by an acquaintance; very well written, this guy knows what hes talking about.

 

[imagoon]

http://hddscan.com/doc/HDD_Tracks_and_Zones.html


article by an acquaintance; very well written, this guy knows what hes talking about.

Neat, but it doesn't mention a STW-less method. The self servo seems to work on the premise that you STW a single platter, kick off a special mode where the drive reads that one platter and duplicates the servo pattern to the other platters. I suspect that would be faster than using an STW on all surfaces.

Cool idea though, multiple copies like that should be pretty redundant and might even be repairable by disk firmware.

I need the read the rest later.

 

[Russwinters]

well because of platters not being 100% identical servo for each platter is generated individually now.

as for article on what they are using to write servo, it is difficult to come by because manufacturers work extra hard to try to keep a lot of their functions a secret.

http://www.google.com/patents?id=jEMGAAAAEBAJ&printsec=abstract&zoom=4#v=onepage&q&f=false

came by this one googling around just now, kind of talks about it, but in this patent more for "repairing servo"

basically seagates have manufacturer commands interface, there is a level /9 that is "SPW mode" or "servo pack-writer". these commands in this level can perform servo writing, but it hasn't really be explored/used in my field due to it not really being for recovery.

you can search arround for command lists for seagates, they changed architecture at the 7200.11 line (hence the boat loads of firmware failures that occured around then) so the commands changed as well.

due to the big 7200.11 failures, this command interface got a lot more "prime time" then seagate wanted, so now there is talk that they are moving the hide this command interface, or remove it completely in the future.

 

[imagoon]

Makes sense. However if you have a drive designed around SSW from the factory, I would think you could make the drive self heal servo data. It should be able to read the information off the other disk surfaces and correct the bad spot.

I can guess why the manufactures would hide that though. You would have people like the OP who would feel there is some need to rewrite it to refresh it. What is funny is the servo information is written at the factory and is likely the oldest information on the disk yet people are worried about data bit rot. If you lose to much of the servo information the drive just shuts down...