Low-Level Formatting

Replies

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  whiz.kid.aniket

  Low-Level Formatting (LLF) can be done either of floppy or your old hard disks (The one which were manufactered before 1995, LLF of modern Hard disks is i guess difficult/impossible...correct me if i am wrong). LLF merely involves subdividing each track on the disk into one or more blocks which would contain the user data and associated control information. If any sectors which cannot be written to and read back from the drive is detected then every sector of the drive is written to; usually by writing a zero byte to every addressable location on the disk.
  
  High-Level Formatting - It is done to detect and logically manipulate bad sectors of hard disk.
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  Morningdot Hablu

  As far what i know you can't delete and remove bad sectors.You just have to find and skip them.So that your data is secured.
  It's impossible to delete and remove bad sectors in the case of physical bad sector.
  You may correct the soft bad sectors by using HD diagnostic tool.It will simply replace you bad sectors with next spare sectors.
  .
  Correct me if i am wrong...!!
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  sushant005

  whiz.kid.aniket

  High-Level Formatting - It is done to detect and correct bad sectors of hard disk.

  But i don't think it is used for correcting bad sectors but ya it is used for detecting bad sectors.If you have any justification then please share with us how is it used for correcting. A physical bad sector can never be corrected but ya it should be detected by third-party software.
  
  do me correct if i m wrong!
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  sushant005

  @ Mohit I also think so it is only used for detecting not for correcting.
  I think that if there is a concept of servo signal which is embedded in each track if we format it physically then this servo signal would be erased and it leads to the crash of hard disk because servo is used to guide the head. So i think it is just used for the detecting not correcting.And in case of FAT file system it just detect the bad sector and update it to the FAT's bad sector table such that when high level formatting is done it just skip that bad sector which is contained in the table.
  
  Any one having another reason please do share.
  Do me correct if i m wrong!
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  whiz.kid.aniket

  @mohit
  @sushant
  
  Ya..you are right it is impossible to correct physical bad sector! Sorry for my mistake.
  
  
  
  

  In case of FAT file system it just detect the bad sector and update it to the FAT's bad sector table such that when high level formatting is done it just skip that bad sector which is contained in the table.

  But, there are some 3rd party tool which helps you logically repair bad sector! It does automatic remapping of sectors. The logic behind this is may be that even if a sector cannot be read normally, it may still be readable with data recovery methods. However, if a drive knows that a sector is bad, it will not reuse that sector and instead remap it to one of its spare-sector regions. This may be the reason why hard disks continue to have sector errors (mostly disk controller timeouts) until all the bad sectors are remapped, typically with an entire-drive zeroing of sectors.