bad sectors

[praveendasika]

what are these bad sectors? why do we get them?i lost 20 mb to bs,i want to know how we can prevent them ,can i now use my 40 gb hard disk ..

[neta1o]

Originally posted here by praveendasika
what are these bad sectors? why do we get them?i lost 20 mb to bs,i want to know how we can prevent them ,can i now use my 40 gb hard disk ..

If you are running windows and you get a bad sector windows will simply not allow access to those sectors. The only way to get them back is to try WinDoctor(Symantec) or to Low-Level format your drive. You can get bad sectors from hardware problems, which is the most common, and low-level format will not fix in that situation. Or software, in which either of the two methods above will fix. Best way to avoid bad sectors is to do frequent scandisks and defragments.

hope this helps-neta1o

[tampabay420]

bad sectors (unless scandisk is incorrect) are physically broken parts of the HDD
correct me if i'm wrong... is there anything else that could cause a bad sector?

[AciDriveHB]

I've seen hard drives that people had let run and run with Windows on it since they got the computer (I'm talking recently seen a computer that was like 8 years old) with a ton of bad sectors. I actually was able to fix them by doing a typical format c:\ on the drive and installing the OS from scratch (which technically would be the first time since it was installed from the factory). I concluded that it might have been due to a "cluster f**k" of information that was being added and deleted over the years.

I've only seen it twice in my life though, every other time it was simply a bad hard drive, or a drive that was dying.

[tampabay420]

ooh, AciDriveHB, maybe you could take an image of your HDD instead of reinstalling?
any thoughts, that could work?

[Darksnake]

Low-level formatting can not be done by the end user, unless the drive is very old. Newer hard drives can not be low level formatted unless you want a paper weight. There are tools that will do a 'low level' format, but this isnt a low level format. This format is actually a form of high-level format in which the sectors are over written with zero's or what is specified by the manufacturer. From my experience this will not fix any truly bad sectors, meaning there is a physical problem with that portion of the disk.

[neta1o]

Low-level formatting can not be done by the end user, unless the drive is very old. Newer hard drives can not be low level formatted unless you want a paper weight. There are tools that will do a 'low level' format, but this isnt a low level format.

Untrue, all hard drives can be low level formatted. When performing this operation it makes the drive the same as when it left the factory. There is numerous utilities that can successfully perfrom this and many BIOS's have an options to perform this. NOTE: PERFORMING THIS WILL RENDER YOUR DATA UN-RECOVERABLE. Although, this shouldn't be used unless it is a last resort.

neta1o

[Reference]

[rcgreen]

bad sectors (unless scandisk is incorrect) are physically broken parts of the HDD
correct me if i'm wrong... is there anything else that could cause a bad sector?

It's not as common as it once was, but if a drive is misconfigured
in the BIOS setup, the computer might be able to access part of it,
but would label everything beyond a certain point as "bad sectors"
I've seen this happen.

But ordinarily, if the drive is detected properly by the BIOS, bad sectors
are physically bad, and you should trash the drive.

Low-level formatting can not be done by the end user

hard drives can be low level formatted

This controversy has come about because there are two completely
different definitions of the term "low level format".

Low level format, in the classical sense, is to write data between
the sectors, to guide the controller in finding sectors and tracks.
If any of these inter-sector bytes are damaged, the sector cannot be read.

On the old MFM and RLL drives (they had two ribbon cables) , you could
run a program like gibson spinrite, and redefine the sectors,
but on modern drives you cannot.

Todays "low level format" utilities, from the drive manufacturers,
wipe all the data sectors, including the master boot record,
but they do not rewrite the inter-sector markings, and therefore
are not a true low level format, in the old-timer's sense.