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Message |
| Al... |
 Posted: Fri Oct 09, 2009 9:55 pm |
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Guest
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Hi Folks,
I have been getting into the world of Linux, partly because it has
some quite good tools for dealing with DR. I have been slowly find
ways to do things that I used to do in Windows in Linux.
One of these is the surface test of a hard disk. In WIndows I used to
use Partition Table Doctor, which is a farily generic windows based
surface tester among other things.
The other day I used badblock on a drive that Partition table doctor
had told me had a bad sector, but badblocks failed to find it.
This has got me puzzled. Anyone able to shed any light on why this
might be?
Admittadly the drive only had 1 bad block, but shouldnt the results be
the same?
Cheers in advance,
-Al |
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| DenverD... |
| Posted: Sat Oct 10, 2009 5:21 am |
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Guest
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Al wrote:
Quote: Hi Folks,
I have been getting into the world of Linux, partly because it has
some quite good tools for dealing with DR.
i wonder what DR is and how it relates to your posted problem, but i
can't figure it out from here: http://www.acronymfinder.com/DR.html
and, i wonder how many key strokes you saved by not typing it out..
and, since i've never used nor seen "Partition Table Doctor" i wonder
what forensic tools it uses it determine a sector is bad (how bad?) [i
tried to learn what it does at http://www.ptdd.com/surfacetest.htm,
but couldn't] and i wonder if a Partition Table Doctor's "sector" is
the same as a badblock's "block"..
and, i wonder if you correctly specified the block size when running
badblock [If you set it too low, however, for a
non-destructive-write-mode test, then it's possble for questionable
blocks on an unreliable hard drive to be hidden by the effects of the
hard disk track buffer. cite:
http://linux.about.com/library/cmd/blcmdl8_badblocks.htm]
with all that said, i also wonder which got it wrong Partition Table
Doctor or badblock...and, if the wrong result was due to operator
error or the intrinsic 'bestness' of one program over the other..
finally, if your hard drive is relatively modern you might find
monitoring by the S.M.A.R.T. <http://en.wikipedia.org/wiki/S.M.A.R.T.>
daemon (look for "Smartmontools" for your flavor of linux) isn't more
useful to you (i mean, do you really care if you have one bad block or
10,000 when you have billion still good? what you really care about is
is the disk trustworthy, or not)..
if your distro doesn't have it handy, you can get the source from
http://sourceforge.net/apps/trac/smartmontools/wiki/TocDoc
as always, ymmv.
--
DenverD (Linux Counter 282315) via Thunderbird 2.0.0.23 (20090817),
KDE 3.5.7 "release 72-11", openSUSE Linux 10.3, 2.6.22.19-0.4-default
#1 SMP i686 athlon |
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| Bill Marcum... |
| Posted: Sat Oct 10, 2009 6:36 am |
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Guest
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["Followup-To:" header set to comp.os.linux.misc.]
On 2009-10-10, Al <bigal.nz at (no spam) gmail.com> wrote:
Quote: Hi Folks,
I have been getting into the world of Linux, partly because it has
some quite good tools for dealing with DR. I have been slowly find
ways to do things that I used to do in Windows in Linux.
One of these is the surface test of a hard disk. In WIndows I used to
use Partition Table Doctor, which is a farily generic windows based
surface tester among other things.
The other day I used badblock on a drive that Partition table doctor
had told me had a bad sector, but badblocks failed to find it.
This has got me puzzled. Anyone able to shed any light on why this
might be?
Admittadly the drive only had 1 bad block, but shouldnt the results be
the same?
I wonder if you were running badblocks on the whole drive (/dev/sda) or on
a partition (dev/sda1)? |
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| Chris Davies... |
| Posted: Sat Oct 10, 2009 7:17 am |
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Guest
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DenverD <spam.trap at (no spam) somewhere.dk> wrote:
Disaster Recovery
Chris |
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| DenverD... |
| Posted: Sat Oct 10, 2009 9:17 am |
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Guest
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thanks!!
of course i should have figured that out..
since Winders folks spend a lot of time doing that, and thinking about
it, and talking/writing about it...i can see how they might have 'DR'
as a well worn and widely recognized acronym.......heh.
--
DenverD (Linux Counter 282315) via Thunderbird 2.0.0.23 (20090817),
KDE 3.5.7 "release 72-11", openSUSE Linux 10.3, 2.6.22.19-0.4-default
#1 SMP i686 athlon |
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| Stefan Patric... |
| Posted: Sat Oct 10, 2009 10:42 am |
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Guest
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On Sat, 10 Oct 2009 00:55:52 -0700, Al wrote:
Quote: [snip]
The other day I used badblock on a drive that Partition table doctor had
told me had a bad sector, but badblocks failed to find it.
This has got me puzzled. Anyone able to shed any light on why this might
be?
Maybe, Partition Table Doctor was wrong. FYI, badblocks doesn't read
sectors, per se; it reads blocks. Hence, its name. In any case,
badblocks' nondestructive, read only check, which is the default, isn't
foolproof: You may be able to read the data on a block, but the block
won't accept a write. This is rare, but it happens. The destructive,
read-write checks are more thorough and accurate, but slow. Don't ever
use this check, if you are testing a drive and don't want all the data on
the drive destroyed.
Read the man and info files for badblocks to really know how it works.
In a terminal, type:
man badblocks
or
info badblocks
Stef |
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| Douglas Mayne... |
| Posted: Sun Oct 11, 2009 10:21 am |
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Guest
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On Sat, 10 Oct 2009 00:55:52 -0700, Al wrote:
Quote: Hi Folks,
I have been getting into the world of Linux, partly because it has
some quite good tools for dealing with DR. I have been slowly find
ways to do things that I used to do in Windows in Linux.
One of these is the surface test of a hard disk. In WIndows I used to
use Partition Table Doctor, which is a farily generic windows based
surface tester among other things.
The other day I used badblock on a drive that Partition table doctor
had told me had a bad sector, but badblocks failed to find it.
This has got me puzzled. Anyone able to shed any light on why this
might be?
Admittadly the drive only had 1 bad block, but shouldnt the results be
the same?
Cheers in advance,
-Al
It is my understanding that some drives have a limited set of unused/spare
sectors which can be used to replace bad sectors. Perhaps
the drive noticed the error and automatically replaced it. Or else, it
could be that the Windows tool performed the remap for you. Another Linux
tool to check out is smartctl. That command could possibly shed
some light on what happened. The manual is avaialable: man smartctl.
The native disc tools may also shed some light. For example, Seagate's
SeaTools can give event history for some Seagate drives. Other
manufacturers have similar tools.
Another possibility is that you could be in an intermediate
failure mode. The reported disk read error did occur at that time but it
is readable now, but the sector will probably fail in the near future.
A disk read error is only reported after a series of failed reads by the
OS.
--
Douglas Mayne |
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| Jesse Dorland... |
| Posted: Sat Oct 17, 2009 1:33 am |
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Guest
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On Oct 10, 7:21 am, DenverD <spam.t... at (no spam) SOMEwhere.dk> wrote:
Quote: Al wrote:
Hi Folks,
finally, if your hard drive is relatively modern you might find
monitoring by the S.M.A.R.T. <http://en.wikipedia.org/wiki/S.M.A.R.T.
daemon (look for "Smartmontools" for your flavor of linux) isn't more
useful to you (i mean, do you really care if you have one bad block or
10,000 when you have billion still good? what you really care about is
is the disk trustworthy, or not)..
First off, it's pretty big missive. You gotta kept it short and to the
point. I have some personal experience with badblock. My hard drive
in my laptop Tecra M3 was about 3 years old -- 35 gig. I simply bought
a new one for $60 bucks, and another 1 Gig ram. All in all cost me
about 99 dollars.
Before buying I did lots of research, and many expert agree upon one
point -- if the hard drive is three years older than get a new one.
Software can not fix hardware flaws. |
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