Help explain sudden partition loss

line · Post by **line** » Tue Apr 20, 2010 5:45 pm

Hi,

I hope someone can help me explain this.

A friend needed help following a clean format (XP Home or Pro -> XP Pro) so I suggested I pick up his computer and look at it at my home. He has two hard drives, one 60GB WD for OS (C) and one 250GB Maxtor for data (Z, NTFS, 50% full), both PATA, attached to an old socket 478 motherboard. No encryption involved.

Both drives worked at his place. When I came home, the first thing I wanted was back up the drives, so I took the 250GB drive first and attached it to my computer (XP Pro). I powered up, and much to my surprise the drive did not show up at My Computer. I fired up Disk Management and learned that the drive is being recognized as "Dynamic Disk - Not Readable". I put it back in the friend's system and saw the same issue.

Eventually, I was able to rescue the data with GetDataBack. When polling the drives, GDB saw a "128GB" Dynamic Partition, but after I ran a quick scan (in "Sudden Partition Loss" mode) it found the 250GB NTFS partition and let me recover the data fully. I surveyed some files (images & checksum-backed files like ZIP archives and FLAC media) and found them healthy.

Can anyone suggest what could have caused this error in the first place?

Below are SMART readings of the drive before (1), during (2-3) and after (4) the recovery process. SMART always worked, and never indicated a physical error. I never received an IO error, either.

1: http://img232.imageshack.us/img232/5546 ... or6b25.png
2: http://img651.imageshack.us/img651/3406 ... or6b25.png
3: http://img255.imageshack.us/img255/6781 ... or6b25.png
4: http://img88.imageshack.us/img88/6795/5 ... or6b25.png

I can also upload the MBR bits if you tell me how. I'm willing to learn what exactly went wrong. Having said that, I prefer not to do potentially destructive operations because I want to keep the drive in case GDB did miss something. I definitely won't use it anymore, though.

Michael Sandstrom · Post by **Michael Sandstrom** » Tue Apr 20, 2010 7:47 pm

I think your friend's drive is going bad. In my experience a run of CHKDSK will often recover misplaced files enabling the disk to be recovered.

SMART readings don't tell the whole story re drive health.

line · Post by **line** » Wed Apr 21, 2010 3:12 am

I've seen many drives fail, but not like that. Usually the drive develops several bad sectors which leads to sudden partition loss or partial data loss. In rare cases the drive becomes completely unreadable and the only option is to contact a recovery service. But this drive seems healthy! I have had no IO errors while recovering data from it. It's just some bits flipped spontaneously, and I'm unable to explain why.