Dynamic HDD Unreadable in XP

[Guest]

To those interested in helping me recover from a HDD failure, thank you for
your time. After coming back from a weekend when I turned my computer off,
it no longer would boot to my typical installation of Win XP Prox32bit. Upon
loading my secondary installation on another physical disk, I noticed that in
disk management, my other dynamic disk was showing up as "failed" and a new
disk had shown up that was basic and all free space.

To fill you in, I have two hard drives, both dynamic (first mistake), and
each drive has a mix of simple, striped, and spanned volumes. This secondary
windows installation is on a simple volume, and I have important data on a
simple volume on my failed drive.

I ran dmdiag.exe and found that my failed drive has a partition hex of 0x0F.
According to KB 320283, this is the same as 0x05 (extended partition) and
uses Logical Block Address Int 0x13 extensions. At this point I am no longer
concerned with how the MBR was changed. I am however, interested in changing
it back to recover my data and never to use dynamic disks again (not to
mention establish a backup plan). I have downloaded DiskProbe.exe and
examined my boot sectors. Comparing my "good drive" to my bad one, there
seems to be quite a few differences. I would cut and paste the info, but it
seems that diskprobe doesn't allow for notepad exportation, etc. I have no
clue what hexadecimal has to do with anything and it has always confused the
crap out of me. I have a theory. I read in KB 329707 that... "Dynamic disks
offer advantages over basic disks, which use the original MS-DOS-style master
boot record (MBR) partition tables to store primary and logical disk
partitioning information. Dynamic disks use a private region of the disk to
maintain a Logical Disk Manager (LDM) database, which contains volume types,
offsets, memberships, and drive letters of each volume. The LDM database is
also replicated, so each dynamic disk knows about every other dynamic disk
configuration. This feature makes dynamic disks more reliable and recoverable
than basic disks." I know this is true because I can still see the volumes
of my failed drive, it will not however recognize that HD as matching with
the missing HD. So my theory is this: I should be able to read the sector on
my good HD that contains the LDM database, then copy that information to my
failed HD, and it will be recognized as dynamically linked again.

If this will not work for me, please let me know... even if you may not have
a better alternative. I am having trouble understanding MS's description of
how to fix my problem as stated in KB 236086 due to what I consider an
inadequate description of how to modify in hex.

Thanks again.

 

[Guest]

http://support.microsoft.com/kb/308424/
http://support.microsoft.com/kb/307889/
Im not all that familiar with dynamic disks myself, see if the above links
apply or can help you..
j;-j

 

[Guest]

Thanks Jaymon, but unfortunately these are too generic of KB's for my
problem. I really need some in depth information into the methodology behind
the LDM and how dynamically linked drives function together.

 

[Guest]

Have at it Kyle, sorry I can't do more.
http://search.microsoft.com/results.aspx?mkt=en-US&setlang=en-US&q=dynamic+disk
http://www.google.com/search?q=dynamic disks
Good luck..
j;-j

 

[Guest]

I think had found a solution: using dskprobe (win XP support tool)
It worked fine to me:

1 - open dskprobe
2 - go to Drives\ Physical Drives...: it opens a new window with
PhysicalDrive0 and PhysicalDrive1 as options(C, D, the hdd installed) ;
select one(double click).
3 - Select handle0 - Set active (and free for editing) -> ok
4 - in the third column of 01C0 you'll found a 42, change it for a 07 - then
go to drives...(see 2 - ) and close handle.
5 - restart
6 - you ll be able to recover the data into the disk. After recover it,
format your disk as basic.

I suppose this is why it is easier to recover them. what you're editing
it's the
patition table, I don't know really what really means this number, but I
suppose it is what tells windows that the disk is dynamic

Nicolas Barros Uriburu

 

[mostafa_aghajani]

Amazing! Thank you ...

It's amazing, thank you.

, you saved a lot of time for me ...
according to Microsoft KB236086 (http://support.microsoft.com/kb/236086) the two value you said before are these:
42: for dynamic disk
07: for basic disk using NTFS file system

but for me, I was sure that my disk was dynamic (I created it in XP) but after changing it back to basic NTFS it worked fine. I think one should ask Microsoft about this

I think had found a solution: using dskprobe (win XP support tool)
It worked fine to me:

1 - open dskprobe
2 - go to Drives\ Physical Drives...: it opens a new window with
PhysicalDrive0 and PhysicalDrive1 as options(C, D, the hdd installed) ;
select one(double click).
3 - Select handle0 - Set active (and free for editing) -> ok
4 - in the third column of 01C0 you'll found a 42, change it for a 07 - then
go to drives...(see 2 - ) and close handle.
5 - restart
6 - you ll be able to recover the data into the disk. After recover it,
format your disk as basic.

I suppose this is why it is easier to recover them. what you're editing
it's the
patition table, I don't know really what really means this number, but I
suppose it is what tells windows that the disk is dynamic

Nicolas Barros Uriburu

 

[onetimeonly]

TestDisk fixed a similarly frustrating problem for me. Open source and free!

http://www.cgsecurity.org/wiki/TestDisk

 

[cezanne81]

Hi,
I have got the same problem (hdd dynamic unreadable). I have got 3 partitions in my hdd. Then i have changed the value from 42 to 07 (in the third column of 01C0 you'll found a 42, change it for a 07). Now, i can see the first partition(h but i cant see the others (i: and j. when i look the disc management partition (h is healthy, the other two partitions (i: and j are unallocated. How can i solve this problem without lost my data.
Best Regards

 

[suthakar]

Dear cezanne81,

I am facing the same problem but i have solved with dskprobe.nut only one partition showing another one is not visible.

Have u solved your problem .

please advice and reply i am having all software backup with that partition only so please guys help me.

cezanne81,i am having problem like your last post have you solved please help me and advice

Thanks and Regards,
Suthakar