RAID-1 and bad sectors?

I just used BootItNG to resize the 2 NTFS partitions on my hard disk. I was
increasing the size of the C drive, so I had to shrink the D drive and slide
it down to the end of the disk. When I did the slide operation, I told it to
slide everything including the unused areas. I ended up getting an "error
reading from hard disk" message. So I retried the slide operation, but just
told it to slide the data only. That worked, so maybe there was a bad sector
in an unused area?

Anyways, I'm now ready to set up RAID-1 in my system. But I'm wondering if
that bad sector might cause a problem in a RAID-1 setup? I know RAID-1 is
supposed help you if a drive fails. But what if a drive doesn't totally stop
working... what if it only develops a few bad sectors? Can RAID-1 handle
that? (I'll be using the HighPoint 370 controller on my Abit KT7-RAID
motherboard.) Like what would happen if the RAID controller is writing some
data, and one of the drives is OK but the other drive has some bad sectors on
it? Can the RAID controller detect the bad sectors and write the data to good
sectors? Or will it not detect the bad sectors and the 2 drives will be
out-of-sync?

wrote in message
...
I just used BootItNG to resize the 2 NTFS partitions on my hard disk. I
was
increasing the size of the C drive, so I had to shrink the D drive and
slide
it down to the end of the disk. When I did the slide operation, I told it
to
slide everything including the unused areas. I ended up getting an "error
reading from hard disk" message. So I retried the slide operation, but
just
told it to slide the data only. That worked, so maybe there was a bad
sector
in an unused area?


Go to the website of the HD's mfg and download the diagnostic utility
and run it.
If *any* errors are found..backup your data and replace the disc.

At any rate...I'd never use a drive with bad sectors in a RAID situation

wrote:

I just used BootItNG to resize the 2 NTFS partitions on my hard
disk. I was increasing the size of the C drive, so I had to
shrink the D drive and slide it down to the end of the disk.
When I did the slide operation, I told it to slide everything
including the unused areas. I ended up getting an "error
reading from hard disk" message. So I retried the slide
operation, but just told it to slide the data only. That
worked, so maybe there was a bad sector in an unused area?

Which may mean that you wrote some of your actual data into a
failing "unused" area, and that that data is now lost or altered.
I wouldn't trust anything that was on that partition.

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"Reply" at the bottom of the article headers." - Keith Thompson
More details at: http://cfaj.freeshell.org/google/

In comp.sys.ibm.pc.hardware.storage wrote:
I just used BootItNG to resize the 2 NTFS partitions on my hard
disk. I was increasing the size of the C drive, so I had to shrink
the D drive and slide it down to the end of the disk. When I did
the slide operation, I told it to slide everything including the
unused areas. I ended up getting an "error reading from hard disk"
message. So I retried the slide operation, but just told it to
slide the data only. That worked, so maybe there was a bad sector
in an unused area?

Anyways, I'm now ready to set up RAID-1 in my system. But I'm
wondering if that bad sector might cause a problem in a RAID-1
setup? I know RAID-1 is supposed help you if a drive fails. But
what if a drive doesn't totally stop working... what if it only
develops a few bad sectors? Can RAID-1 handle that? (I'll be using
the HighPoint 370 controller on my Abit KT7-RAID motherboard.) Like
what would happen if the RAID controller is writing some data, and
one of the drives is OK but the other drive has some bad sectors on
it? Can the RAID controller detect the bad sectors and write the
data to good sectors? Or will it not detect the bad sectors and the
2 drives will be out-of-sync?

It will detect a bad sector only if it reads from it. In that case
it will fail-over to the other disk. Many RAID controllers will
also mark the disk as bad and kick it form the array. If you
have bad sectors on eiter disk in different places that behaviour
is not too desirable, but in this case you are in trouble anyways,
since modern disks only exhibit bad sectors if they are dying or
have very serious problems.

Now, you might be in this situation and then your best bet is
possibly RAID recovery software (have seen some, don't remember
where) or if your controller allows you to disable the kicking on
defects. Linux software RAID seems not to allow you to do that.
What I would do in such a case is to mount both partitions/drives
read-only, determine which has less bad sectors, write them
down and copy that partition/drive to a good one. Then copy
the bad sectors on the first drive from the second one. If
ithe number of bad sectros is high, then script this using,
e.g., badblocks and dd_rescue.

When writing to a bad sector, the data will be written to both drives.
Since the data is written with checksums, the the controller will
recognize a bad sector and read it form the other disk. See also
above.

Arno

wrote:

I just used BootItNG to resize the 2 NTFS partitions on my hard disk.
I was increasing the size of the C drive, so I had to shrink the D
drive and slide it down to the end of the disk. When I did the slide
operation, I told it to slide everything including the unused areas.
I ended up getting an "error reading from hard disk" message. So I
retried the slide operation, but just told it to slide the data only.
That worked, so maybe there was a bad sector in an unused area?

Its important to check that possibility before doing anything else.

Use Everest to check the SMART data for the drive, post it here.
http://www.majorgeeks.com/download.php?det=4181

Also run the hard drive manufacturer's diagnostic on that drive.

It might just have been a quirk of BootItNG, it can be pretty buggy.

Anyways, I'm now ready to set up RAID-1 in my system. But I'm
wondering if that bad sector might cause a problem in a RAID-1 setup?
I know RAID-1 is supposed help you if a drive fails. But what if a
drive doesn't totally stop working... what if it only develops a few
bad sectors? Can RAID-1 handle that? (I'll be using the HighPoint
370 controller on my Abit KT7-RAID motherboard.) Like what would
happen if the RAID controller is writing some data, and one of the
drives is OK but the other drive has some bad sectors on it? Can the
RAID controller detect the bad sectors and write the data to good
sectors? Or will it not detect the bad sectors and the 2 drives will
be out-of-sync?

Dont worry about any of this until you prove that the drive does have bad
sectors.

On Fri, 30 Dec 2005 06:47:22 -0500, "Chuck F. " wrote:

wrote:

I just used BootItNG to resize the 2 NTFS partitions on my hard
disk. I was increasing the size of the C drive, so I had to
shrink the D drive and slide it down to the end of the disk.
When I did the slide operation, I told it to slide everything
including the unused areas. I ended up getting an "error
reading from hard disk" message. So I retried the slide
operation, but just told it to slide the data only. That
worked, so maybe there was a bad sector in an unused area?

Which may mean that you wrote some of your actual data into a
failing "unused" area, and that that data is now lost or altered.
I wouldn't trust anything that was on that partition.

I did back up all my D drive data before I did the resizings of the
partitions. After I resized them, I did a binary comparison of my backups
with the data on the hard drive, and everything looked the same.

What about just using Windows? If Windows writes data to the hard drive, will
it check if it's writing data to a bad sector, or does it not know or care?

On Sat, 31 Dec 2005 05:27:52 +1100, "Rod Speed" wrote:

wrote:

I just used BootItNG to resize the 2 NTFS partitions on my hard disk.
I was increasing the size of the C drive, so I had to shrink the D
drive and slide it down to the end of the disk. When I did the slide
operation, I told it to slide everything including the unused areas.
I ended up getting an "error reading from hard disk" message. So I
retried the slide operation, but just told it to slide the data only.
That worked, so maybe there was a bad sector in an unused area?

Its important to check that possibility before doing anything else.

Use Everest to check the SMART data for the drive, post it here.
http://www.majorgeeks.com/download.php?det=4181

Also run the hard drive manufacturer's diagnostic on that drive.

I have a Samsung SP1213N 120 GB drive, and on their web site they have a
couple utilities for testing hard drives: SHDIAG, which asks you to do a
low-level format if it detects an error (I guess I don't want to use that
one), and HUTIL. They don't say what HUTIL does if it detects an error, but
they say it writes stuff to the disk while testing. Would it overwrite any of
my data?


It might just have been a quirk of BootItNG, it can be pretty buggy.

Anyways, I'm now ready to set up RAID-1 in my system. But I'm
wondering if that bad sector might cause a problem in a RAID-1 setup?
I know RAID-1 is supposed help you if a drive fails. But what if a
drive doesn't totally stop working... what if it only develops a few
bad sectors? Can RAID-1 handle that? (I'll be using the HighPoint
370 controller on my Abit KT7-RAID motherboard.) Like what would
happen if the RAID controller is writing some data, and one of the
drives is OK but the other drive has some bad sectors on it? Can the
RAID controller detect the bad sectors and write the data to good
sectors? Or will it not detect the bad sectors and the 2 drives will
be out-of-sync?

Dont worry about any of this until you prove that the drive does have bad
sectors.

On Sat, 31 Dec 2005 05:27:52 +1100, "Rod Speed" wrote:

Use Everest to check the SMART data for the drive, post it here.
http://www.majorgeeks.com/download.php?det=4181

I just installed this, and under Storage SMART, it doesn't show anything.
It's all gray. And when I right click on SMART, it let's me do a Quick
Report, but it prints stuff out about various other devices and nothing about
the hard drive.

wrote
Rod Speed wrote

Use Everest to check the SMART data for the drive, post it here.
http://www.majorgeeks.com/download.php?det=4181

I just installed this, and under Storage SMART,
it doesn't show anything. It's all gray.

Yeah, you can get that result on some systems.

There's another that isnt too bad on the knoppix bootable CD.

Not as easy to use by quite effective. Bit more difficult to post
the results with that tho if you dont know anything about linux.

See what SHDIAG says first.

And when I right click on SMART, it let's me do
a Quick Report, but it prints stuff out about various
other devices and nothing about the hard drive.

wrote
Rod Speed wrote
wrote

I just used BootItNG to resize the 2 NTFS partitions on my hard
disk. I was increasing the size of the C drive, so I had to shrink
the D drive and slide it down to the end of the disk. When I did
the slide operation, I told it to slide everything including the
unused areas. I ended up getting an "error reading from hard disk"
message. So I retried the slide operation, but just told it to
slide the data only. That worked, so maybe there was a bad sector
in an unused area?

Its important to check that possibility before doing anything else.

Use Everest to check the SMART data for the drive, post it here.
http://www.majorgeeks.com/download.php?det=4181

Also run the hard drive manufacturer's diagnostic on that drive.

I have a Samsung SP1213N 120 GB drive, and on their web
site they have a couple utilities for testing hard drives: SHDIAG,

That one isnt for your drive.

which asks you to do a low-level format if it detects an error
(I guess I don't want to use that one),

Correct, but because it isnt for your drive.

and HUTIL. They don't say what HUTIL does if it
detects an error, but they say it writes stuff to the
disk while testing. Would it overwrite any of my data?

Not if you dont tell it to erase the drive. You say
elsewhere that your data is backed up anyway.

It might just have been a quirk of BootItNG, it can be pretty buggy.

Anyways, I'm now ready to set up RAID-1 in my system. But I'm
wondering if that bad sector might cause a problem in a RAID-1
setup? I know RAID-1 is supposed help you if a drive fails. But
what if a drive doesn't totally stop working... what if it only
develops a few bad sectors? Can RAID-1 handle that? (I'll be
using the HighPoint 370 controller on my Abit KT7-RAID
motherboard.) Like what would happen if the RAID controller is
writing some data, and one of the drives is OK but the other drive
has some bad sectors on it? Can the RAID controller detect the bad
sectors and write the data to good sectors? Or will it not detect
the bad sectors and the 2 drives will be out-of-sync?

Dont worry about any of this until you prove that the drive does
have bad sectors.