Bad Sectors on Hard Drive Questions

[effdee]

Is it possible to mark bad hard drive sectors as "bad" so the system won't
use them? and how do I do it?

If I delete the partition and then recreate it and format it fresh, are the
bad sectors used? or are they marked as bad during the format?

effdee








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[GTS]

If you run chkdsk /r it will mark out the bad sectors. Note though that
once a drive starts to develop bad sectors it will usually continue to
develop more. It's best to replace it.

 

[Guest]

Is it possible to mark bad hard drive sectors as "bad" so the system won't
use them? and how do I do it?

If I delete the partition and then recreate it and format it fresh, are the
bad sectors used? or are they marked as bad during the format?

effdee

when you run scandisk it marks any bad sectors as 'dont use' if you do
a high level format that will erase the mbr where that info is stored,
creating/removing partitions would not remove bad block info.

Flamer.

 

[Guest]

Related question. I have a partition with bad sectors on it, had the OS on
it and crashed. I loaded a ghost image on naother partition but I cannot
Format the bad partition. Perhaps it is still loading some files somewhere on
boot? For the time being I have used TweakUI to hide the drive but I would
prefer to format it.

Maybe I should just let it stay hidden?

 

[Rock]

when you run scandisk it marks any bad sectors as 'dont use' if you do
a high level format that will erase the mbr where that info is stored,
creating/removing partitions would not remove bad block info.

There is no scandisk in XP. It's chkdsk.

 

[Rock]

Related question. I have a partition with bad sectors on it, had the OS on
it and crashed. I loaded a ghost image on naother partition but I cannot
Format the bad partition. Perhaps it is still loading some files somewhere
on
boot? For the time being I have used TweakUI to hide the drive but I would
prefer to format it.

Maybe I should just let it stay hidden?

Replace the drive.

 

[Jonny]

Is it possible to mark bad hard drive sectors as "bad" so the system won't
use them? and how do I do it?

If I delete the partition and then recreate it and format it fresh, are
the bad sectors used? or are they marked as bad during the format?

I use a zero write utility from the HD's manufacturer's website. "Bad
areas" are mapped out. If extensive, will refuse to go any further. And
will recommend replacement of the hard drive.

 

[Dave B.]

If your going to post replies, please use the proper terminology for the OS
in question to avoid further confusing the OP. XP has no scandisk, it is
called chkdsk.

 

[frodo]

Hard drives have evolved over the years. Today, HDs map out bad sectors
all by themselves, w/o the OS knowing about it at all. Only when the HD
runs out of spares will it report a bad sector to the OS, then the OS
becomes responsible for mapping out that sector. At that point the drive
is in bad shape.

So, _IF_ chkdsk is reporting bad sectors to you then the HD has used up
its reserve of spare sectors, and the drive is definately on its way out.
Using a SMART reporting utility for your HD (if you can find one) you can
see the state of the "reserve pool" of sectors. Most SMART tools will
declare the drive as "failed" if the pool is empty.

Doing a full format (w/ "scan for bad sectors" checked) effectively forces
the HD to check every sector on the disk and map it out if it's bad.
While this may seem like a good thing, it's really not. If will force the
HD to use up a spare sector from the pool for every bad sector on the
drive, even if that sector isn't holding user data (and it may never hold
user data, given the huge size of today's disks). Better to do a quick
format and then let the drive detect bad sectors only when they are
actually used. This way the pool is only used when actually needed.

[At manufacturing time the whole drive is low-level formated, and ALL bad
sectors are detected at that time; if the resulting pool of spares is "too
small" the drive is rejected and never sold. Over time as new sectors go
bad the pool gets used up.]

 

[Jonny]

Hard drives have evolved over the years. Today, HDs map out bad sectors
all by themselves, w/o the OS knowing about it at all. Only when the HD
runs out of spares will it report a bad sector to the OS, then the OS
becomes responsible for mapping out that sector. At that point the drive
is in bad shape.

So, _IF_ chkdsk is reporting bad sectors to you then the HD has used up
its reserve of spare sectors, and the drive is definately on its way out.
Using a SMART reporting utility for your HD (if you can find one) you can
see the state of the "reserve pool" of sectors. Most SMART tools will
declare the drive as "failed" if the pool is empty.

Doing a full format (w/ "scan for bad sectors" checked) effectively forces
the HD to check every sector on the disk and map it out if it's bad.
While this may seem like a good thing, it's really not. If will force the
HD to use up a spare sector from the pool for every bad sector on the
drive, even if that sector isn't holding user data (and it may never hold
user data, given the huge size of today's disks). Better to do a quick
format and then let the drive detect bad sectors only when they are
actually used. This way the pool is only used when actually needed.

[At manufacturing time the whole drive is low-level formated, and ALL bad
sectors are detected at that time; if the resulting pool of spares is "too
small" the drive is rejected and never sold. Over time as new sectors go
bad the pool gets used up.]

"High level" tools in the OS can record what areas not to use at the OS
level. The spares are not used in this case to replace the bad area. All
data is lost at the OS level as a consequence in the bad area. This has
limitations in the amount of non-use areas. Its not foolproof.

"Low level" tools (zerofill or diagnostic utility for instance) record what
areas not to use, and what is available for use in reserve. Usually in map
form, telling the controller itself. The bad area is remapped to use the
spare area. The file data, as is, is read, will be placed in the spare area
as well. The OS never sees this process, just the results.

A bad sector usually has adjoining or soon to join bad sector friends.
Backup your data, get a replacement hard drive soon.

 

[effdee]

The drive I'm having trouble with is 200gig.
Anyone know about how much space would be available for bad sector
replacement on this?
I've only had it a year, surely it can't have run out already?
effdee

Hard drives have evolved over the years. Today, HDs map out bad sectors
all by themselves, w/o the OS knowing about it at all. Only when the HD
runs out of spares will it report a bad sector to the OS, then the OS
becomes responsible for mapping out that sector. At that point the drive
is in bad shape.

So, _IF_ chkdsk is reporting bad sectors to you then the HD has used up
its reserve of spare sectors, and the drive is definately on its way out.
Using a SMART reporting utility for your HD (if you can find one) you can
see the state of the "reserve pool" of sectors. Most SMART tools will
declare the drive as "failed" if the pool is empty.

Doing a full format (w/ "scan for bad sectors" checked) effectively
forces
the HD to check every sector on the disk and map it out if it's bad.
While this may seem like a good thing, it's really not. If will force
the
HD to use up a spare sector from the pool for every bad sector on the
drive, even if that sector isn't holding user data (and it may never hold
user data, given the huge size of today's disks). Better to do a quick
format and then let the drive detect bad sectors only when they are
actually used. This way the pool is only used when actually needed.

[At manufacturing time the whole drive is low-level formated, and ALL bad
sectors are detected at that time; if the resulting pool of spares is
"too
small" the drive is rejected and never sold. Over time as new sectors go
bad the pool gets used up.]

"High level" tools in the OS can record what areas not to use at the OS
level. The spares are not used in this case to replace the bad area. All
data is lost at the OS level as a consequence in the bad area. This has
limitations in the amount of non-use areas. Its not foolproof.

"Low level" tools (zerofill or diagnostic utility for instance) record
what areas not to use, and what is available for use in reserve. Usually
in map form, telling the controller itself. The bad area is remapped to
use the spare area. The file data, as is, is read, will be placed in the
spare area as well. The OS never sees this process, just the results.

A bad sector usually has adjoining or soon to join bad sector friends.
Backup your data, get a replacement hard drive soon.
--
Jonny



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[Rock]

The drive I'm having trouble with is 200gig.
Anyone know about how much space would be available for bad sector
replacement on this?
I've only had it a year, surely it can't have run out already?
effdee

There is no set time for drive failure. It can last for many years or fail
in a week.

 

[Bob I]

It doesn't matter, contact the drive manufacturer if the unit is still
under warranty.

The drive I'm having trouble with is 200gig.
Anyone know about how much space would be available for bad sector
replacement on this?
I've only had it a year, surely it can't have run out already?
effdee

Hard drives have evolved over the years. Today, HDs map out bad sectors
all by themselves, w/o the OS knowing about it at all. Only when the HD
runs out of spares will it report a bad sector to the OS, then the OS
becomes responsible for mapping out that sector. At that point the drive
is in bad shape.

So, _IF_ chkdsk is reporting bad sectors to you then the HD has used up
its reserve of spare sectors, and the drive is definately on its way out.
Using a SMART reporting utility for your HD (if you can find one) you can
see the state of the "reserve pool" of sectors. Most SMART tools will
declare the drive as "failed" if the pool is empty.

Doing a full format (w/ "scan for bad sectors" checked) effectively
forces
the HD to check every sector on the disk and map it out if it's bad.
While this may seem like a good thing, it's really not. If will force
the
HD to use up a spare sector from the pool for every bad sector on the
drive, even if that sector isn't holding user data (and it may never hold
user data, given the huge size of today's disks). Better to do a quick
format and then let the drive detect bad sectors only when they are
actually used. This way the pool is only used when actually needed.

[At manufacturing time the whole drive is low-level formated, and ALL bad
sectors are detected at that time; if the resulting pool of spares is
"too
small" the drive is rejected and never sold. Over time as new sectors go
bad the pool gets used up.]

"High level" tools in the OS can record what areas not to use at the OS
level. The spares are not used in this case to replace the bad area. All
data is lost at the OS level as a consequence in the bad area. This has
limitations in the amount of non-use areas. Its not foolproof.

"Low level" tools (zerofill or diagnostic utility for instance) record
what areas not to use, and what is available for use in reserve. Usually
in map form, telling the controller itself. The bad area is remapped to
use the spare area. The file data, as is, is read, will be placed in the
spare area as well. The OS never sees this process, just the results.

A bad sector usually has adjoining or soon to join bad sector friends.
Backup your data, get a replacement hard drive soon.
--
Jonny



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[/QUOTE]