RAID-1 and bad sectors?

[void]

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?

 

[philo]

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

 

[Chuck F.]

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/>

 

[Arno Wagner]

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

 

[Rod Speed]

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.

 

[void]

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?

 

[void]

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?

 

[void]

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.

 

[Rod Speed]

(e-mail address removed) wrote

Rod Speed (e-mail address removed) wrote

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.

 

[Rod Speed]

(e-mail address removed) wrote

Rod Speed (e-mail address removed) wrote

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.

 

[Eric Gisin]

In SCSI RAID 1/5, the drives often have bad sector reallocation turned off.
The RAID firmware regenerates the data when a bad sector shows up,
issues a REASSIGN command, and writes the correct data to a fresh sector.

SATA-2 probably can do the same thing, but more likely ATA/SATA RAID
just rewrites the correct data and the drive reallocates automagically.

 

[ohaya]

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?

Hi,

I ran HUTIL on my Samsung SP2014N a couple of weeks ago, and when it
found what it said was a bad sector, I think that the warning msg said
that it would write all zeroes to that sector if I answer 'yes'. I was
right in the middle of a bunch of things, so I don't remember exactly,
but I know that I decided NOT to tell it 'yes'.

Jim

 

[void]

OK, I just ran HUTIL and got some errors (see below). Is there any way to
tell if those bad sectors have data on them or if they're not being used?



[SELF DIAGNOSTIC (Hutil v2.00)]
Model Name : SAMSUNG SP1213N
Rom Revision : TL100-24
Drive Size : 114498MB (LBA : 234493056)
Start Time : Fri Dec 30 20:57:49 2005


-------------------------------------------------
Test Loop Number : 1/1
-------------------------------------------------C:42962 H:0 S:547 Error : Ecc error
C:42962 H:0 S:548 Error : Ecc error
C:42962 H:0 S:549 Error : Ecc error
C:42962 H:0 S:550 Error : Ecc error
C:42962 H:0 S:551 Error : Ecc error
C:42962 H:0 S:552 Error : Ecc error
C:42962 H:0 S:553 Error : Ecc error
C:42962 H:0 S:554 Error : Ecc error
C:42962 H:0 S:555 Error : Ecc error
C:42962 H:0 S:556 Error : Ecc error
C:42962 H:0 S:557 Error : Ecc error
C:42962 H:0 S:558 Error : Ecc error
C:42962 H:0 S:559 Error : Ecc error
C:42962 H:0 S:560 Error : Ecc error
C:42962 H:0 S:561 Error : Ecc error
C:42962 H:0 S:562 Error : Ecc error
C:42962 H:0 S:563 Error : Ecc error
C:42962 H:0 S:564 Error : Ecc error
C:42962 H:0 S:565 Error : Ecc error
C:42962 H:0 S:566 Error : Ecc error
C:42962 H:0 S:567 Error : Ecc error
C:42962 H:0 S:568 Error : Ecc error
C:42962 H:0 S:569 Error : Ecc error
C:42962 H:0 S:570 Error : Ecc error
C:42962 H:0 S:571 Error : Ecc error
C:42962 H:0 S:572 Error : Ecc error
C:42962 H:0 S:573 Error : Ecc error
C:42962 H:0 S:574 Error : Ecc error
C:42962 H:0 S:575 Error : Ecc error
C:42962 H:0 S:576 Error : Ecc error
C:42962 H:0 S:577 Error : Ecc error
C:42962 H:0 S:578 Error : Ecc error
Error : This drive has some defects.

Scan Elapsed Time : 00:41:49
Error Occured Test Loop Number 1
End Time : Fri Dec 30 21:41:55 2005
Test was completed.
=================================================

 

[Rod Speed]

(e-mail address removed) wrote

OK, I just ran HUTIL and got some errors (see below).
Is there any way to tell if those bad sectors have data
on them or if they're not being used?

Hitachi's DFT does tell you what files particular bads are in
from memory. Dont currently have a drive with bads to check.

Why do you care ? You said you have the data fully backed up.

It would be worth checking the drive with some other diag like
DFT, those numbers look suspicious, all at the extreme range
of the cylinders, all on one head, with increasing sector numbers.

I'd personally get the SMART data somehow, by using
smartctl when using the knoppix CD and decide whether
to RMA the drive if its clearly failing, like it looks like it is.

If the data is fully backed up, I'd personally write zeros thru the
drive and see if that will get the drive to reallocate the bads, but
thats too many bads for my taste, it looks like its dying.

[SELF DIAGNOSTIC (Hutil v2.00)]
Model Name : SAMSUNG SP1213N
Rom Revision : TL100-24
Drive Size : 114498MB (LBA : 234493056)
Start Time : Fri Dec 30 20:57:49 2005


-------------------------------------------------
Test Loop Number : 1/1
-------------------------------------------------C:42962 H:0 S:547 Error : Ecc error
C:42962 H:0 S:548 Error : Ecc error
C:42962 H:0 S:549 Error : Ecc error
C:42962 H:0 S:550 Error : Ecc error
C:42962 H:0 S:551 Error : Ecc error
C:42962 H:0 S:552 Error : Ecc error
C:42962 H:0 S:553 Error : Ecc error
C:42962 H:0 S:554 Error : Ecc error
C:42962 H:0 S:555 Error : Ecc error
C:42962 H:0 S:556 Error : Ecc error
C:42962 H:0 S:557 Error : Ecc error
C:42962 H:0 S:558 Error : Ecc error
C:42962 H:0 S:559 Error : Ecc error
C:42962 H:0 S:560 Error : Ecc error
C:42962 H:0 S:561 Error : Ecc error
C:42962 H:0 S:562 Error : Ecc error
C:42962 H:0 S:563 Error : Ecc error
C:42962 H:0 S:564 Error : Ecc error
C:42962 H:0 S:565 Error : Ecc error
C:42962 H:0 S:566 Error : Ecc error
C:42962 H:0 S:567 Error : Ecc error
C:42962 H:0 S:568 Error : Ecc error
C:42962 H:0 S:569 Error : Ecc error
C:42962 H:0 S:570 Error : Ecc error
C:42962 H:0 S:571 Error : Ecc error
C:42962 H:0 S:572 Error : Ecc error
C:42962 H:0 S:573 Error : Ecc error
C:42962 H:0 S:574 Error : Ecc error
C:42962 H:0 S:575 Error : Ecc error
C:42962 H:0 S:576 Error : Ecc error
C:42962 H:0 S:577 Error : Ecc error
C:42962 H:0 S:578 Error : Ecc error
Error : This drive has some defects.

Scan Elapsed Time : 00:41:49
Error Occured Test Loop Number 1
End Time : Fri Dec 30 21:41:55 2005
Test was completed.
=================================================

 

[void]

(e-mail address removed) wrote


Hitachi's DFT does tell you what files particular bads are in
from memory. Dont currently have a drive with bads to check.

Why do you care ? You said you have the data fully backed up.

If I can determine that those bad sectors are in unused areas, then I can
"ghost" the drive to my new SP1213N, which I also ran HUTIL on and it has no
problems. That's much easier than spending time to re-install the OS and
re-install and re-configure a ton of applications.

I also need to determine how BootItNG deals with writing data to bad sectors,
and how Windows deals with reading and writing data from bad sectors. That
will help me determine if my data still has integrity or not.

It would be worth checking the drive with some other diag like
DFT, those numbers look suspicious, all at the extreme range
of the cylinders, all on one head, with increasing sector numbers.

I'd personally get the SMART data somehow, by using
smartctl when using the knoppix CD and decide whether
to RMA the drive if its clearly failing, like it looks like it is.

What will the SMART data tell me?

If the data is fully backed up, I'd personally write zeros thru the
drive and see if that will get the drive to reallocate the bads, but
thats too many bads for my taste, it looks like its dying.

The reviews on newegg.com for these Samsung drives aren't great. I have no
confidence that my new SP1213N won't develop the same problems.

 

[Rod Speed]

(e-mail address removed) wrote

If I can determine that those bad sectors are in unused areas, then
I can "ghost" the drive to my new SP1213N, which I also ran HUTIL
on and it has no problems. That's much easier than spending time to
re-install the OS and re-install and re-configure a ton of applications.
OK.

I also need to determine how BootItNG deals with writing data to bad sectors,

The hard drive should handle that behind BootItNG's back.

and how Windows deals with reading and writing data from bad sectors.

The hard drive should handle the writing behind Win's back.

That will help me determine if my data still has integrity or not.

What will the SMART data tell me?

Basically confirm that the drive is dying.

The reviews on newegg.com for these Samsung drives aren't great.

I've never believed those reviews myself.

I have no confidence that my new SP1213N
won't develop the same problems.

None of mine have. And the storagereview reliablity database
shows that plenty dont have any problems with their drives too.

And the result with many of their competitors drives are
much worse, particularly the maxtor drives of the same size.

The seagate 7200.7s do better, but the 7200.8s are obscenely bad.

 

[void]

The hard drive should handle that behind BootItNG's back.


The hard drive should handle the writing behind Win's back.

So the hard drive will detect a bad sector and then find a good sector to
which to write the data? Based on what Chuck F. said, the hard drive will
just write the data to whichever sector, even if its bad.

Basically confirm that the drive is dying.

Seems like a safe assumption.

None of mine have. And the storagereview reliablity database
shows that plenty dont have any problems with their drives too.

And the result with many of their competitors drives are
much worse, particularly the maxtor drives of the same size.

The seagate 7200.7s do better, but the 7200.8s are obscenely bad.

Thanks for pointing out storagereview.com. Looks like the Samsungs are near
the bottom third. The Seagate 7200.7s are near the top. Maybe I'll get a
couple of those.

 

[void]

Thanks for the informative post, Arno.

 

[Rod Speed]

(e-mail address removed) wrote

So the hard drive will detect a bad sector and then
find a good sector to which to write the data?
Yes.

Based on what Chuck F. said, the hard drive will just
write the data to whichever sector, even if its bad.

Its more complicated than that.

Seems like a safe assumption.

It aint about assumptions. You can get what
appear to be bad sectors for other reasons.

Thanks for pointing out storagereview.com.
Looks like the Samsungs are near the bottom third.

There's plenty in the bottom 10%

 

[void]

(e-mail address removed) wrote


Its more complicated than that.

Could you elaborate? Seems like you and Chuck F. have made contradictory
statements.

It aint about assumptions. You can get what
appear to be bad sectors for other reasons.

But all those "ecc errors" indicate my drive is defective in some way, no?