I'm wanting to backup my WinXP partition, preferably to another partition on
the same drive.
(I have a specific reason for wanting to do a backup with this approach.)
I prepared enough space to prepare for it (stealing uneeded space from Linux
and getting rid of a NTFS "data drive" that I only used for DVD writing
preperation, etc). Now, in order to consolidate the free space in one
location, I need to shift the WinXP (NTFS) partition. (I'm using
PartitionMagic 8.0.)
I defragged the WinXP partition and ran chkdsk to prepare it for it's move,
but PartitionMagic refuses to move it. PartitionMagic finds "bad sectors"
in the WinXP partition and says it can't be safely moved. I tried several
variations of using PartitionMagic, from running it from within WinXP (which
means a reboot, startup process to move the partition) to running it from a
small Win98 partition on the same drive (which means it could do the move
from within Windows without having to do a startup process). Either way, is
same result: "bad sectors".
The "bad sectors" warning from PartitionMagic, of course, made me
immiedietly think the drive was crapping out. I ran chkdsk again, and sure
enough it said there were "bad sectors" (4096 bytes worth) as well. I ran
chkdsk in several variations, "chkdsk /f" as a reboot startup process and
"chkdsk /r" from WinXP's Recovery Console. Same thing every way.
Next, to get more info about the status of the drive, I ran the
manufacturer's (IBM/Hitachi) Drive Fitnest Test. I also ran Spinrite 6.0
against the drive. I also checked the S.M.A.R.T. status of the drive.
Everything is reporting that the drive is 100% healthly, with zero bad
physical sectors. They also report that that the "reserve sector cache" are
completly unused. All of the "working sectors" on the drive are fine, there
is no need for any of the reserve to be used. (Modern drives automatically
map a "reserve sector" from the cache when one of "working sectors" go
physically bad. This is controlled by the drive controller and should be
completetly invisible from the OS.) I ran these programs against the entire
drive and each seperate partition, all with same results. The drive is
fine.
This is leading me to believe that my problem with the WinXP (NTFS)
partition isn't bad physical sectors, but "bad" logical sectors. The way I
understand how sectors work is that each sector stores a cyclic redunancy
check value in an ECC byte, that should be the same value of all the sum of
the rest of the bytes in the sector. If the two values are different, then
it appears "bad" to the OS. If power is inadvertently lost during a write
sequence to a sector, the two values become different -- and the sector
appears bad to the OS. While not physically bad, it becomes logically bad
to the OS. I've lost power a few times in WinXP, so I really think this is
probably whats going on. I've also seen "bad" logical sectors in Win98 and
Win95 in the past, but Scandisk always seemed to fix them. WinXP, if
installed as NTFS filesytem, doesn't have Scandisk -- it only has chkdsk.
Chkdsk seems to be very lacking about it's reporting. It doesn't tell you
which actual sectors are "bad". It doesn't even tell you how many sectors
are "bad". It says 4096 bytes, but if my understanding is correct then
chkdsk reports an entire cluster as bad if even only one sector within is
bad. (My NTFS cluster size is 4096 bytes.) I'm assuming there would be 8
sectors to cluster: 512 * 8 = 4096?
Once I get working backup, I plan on reformating this partition and
re-installing WinXP -- along with doing the "Check for Bad Sectors" test
during the install. After installing, if chkdsk reports zero bad sectors
(and the other programs still say no reserves are being used), then it was
definetly just bad "logical" sectors.
I can't get a working backup of this WinXP (NTFS) with these "bad sectors"
though. I've been trying everything, including using a raw disk editor and
attempting to poke around the NTFS meta-files ($badclus, $bitmat, etc).
I've searched Google and Deja to no end looking for a way to clear up "bad"
logical sectors in WinXP NTFS, without having to format. I do have Norton
Systemworks, which worked great for this very problem in Win95/98, but Disk
Doctor can only scan for drive problem with WinXP's NTFS. For repairing
them, it resorts to using WinXP's native chkdsk as a startup process.
(Well, at least my version anyway. Norton Systemworks 2002, which I have
kept updated since then through yearly subscriptions. If anyone has Norton
2005 and knows if Disk Doctor works natively with repairing drive errors,
I'd be more than appreciate in knowing.)
PartitionMagic 8.0 simply will not do it. Its very anal about partitions
being absolutely perfect before working with them. (Which is probably a
good thing.) I've tried everything though, including launching
PartitionMagic with the "/IFC" switch which is supposed to ignore file check
errors.
As per chkdsk and PartitionMagic, the only error on this partition are these
"bad" sectors. Chkdsk did find one cross-linked file the first time I ran
it, but it did repair that.
I've read that Ghost (and/or Drive Image) has the ability to strip "bad"
logical sectors when you make an image? I wasn't able to ascertain if it
can do this with NTFS or just FAT32 though. If so, I'll definetly be
purchasing it. I've seen them both on the shelves at my university's
computer store. (Got to love "Academic pricing"). If these sectors are
stripped though, when (if I'm thinking right), there will be a file
corrupted. I'd like to know which file is actually living across these
"bad" sectors before corrupting it even further, so I could delete and
restore it from an original source afterwards. I've also searched, to no
end, for how to figure out which file is associated with specific sectors on
a drive. The only thing I've found is that information lives "somewhere in
the meta-files", which I've been poking around (not changing anything) with
a raw disk editor. Without taking a file-structure design course (geared to
wards NTFS), I'm thinking I'm probably at a dead end with that approach. I
can't find much information on the web, even Microsoft's Knowledge Base
isn't talking. I thought I had a "breakthrough" at one point after reading
about a Microsoft undocumented and "internal use only" program called
"diskedit.exe" (not to be confused with Norton's Diskedit) that could this
very task (along with associating NTFS filenumbers with actual filenames),
but after finally digging that program up it only works with WinNT's NTFS
and not WinXP's.
Any help, other than saying to format (which is not an option I can
consider), is most appreciated!
Thanks..
-Eric


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