I have a Asus P6T Deluxe V2 motherboard (X58 chipset, i7 930 cpu). I've been using the RAID controller on the MB (Intel Matrix ICH10R) with a pair of 1.5T drive in RAID1 mirroring mode for years without issue. I also have a 2TB WD RED drive in non-raid mode (for DVR files), and about a year ago upgraded that 2TB to a 4TB drive. All these are data drives as Windows boot from a SSD.
Few days ago, both NTFS partitions on that 4TB drive changed to 'raw' partitions, all of a sudden! I spend the entire weekend trying to recover its content (what I thought was not important, become very important when I no longer have it
and in the process, accidentally discovered what I believe to be the true cause of the corruption. Not virus, not bad drive, not corrupted OS, but because of using a 4TB drive partitioned and formatted elsewhere on the damned Intel RAID controller (that apparently doesn't properly recognize the drive and only reported 1.5T).
When I installed the 4TB drive a year ago, I first tested it using my external HD dock, which apparently used the Marvel SATA controller on my MB, which is entirely separate from the internal Intel SATA/RAID controller. After 2 weeks of testing, I moved the HD inside the PC, which is using the Intel Matrix controller because I had 2 other drives in RAID1 mode.
What I did not notice is that after the switch, the BIOS only reported 1.5T, but Windows still sees it as a 4TB drive because it's already partitioned. I used it happily for over a year, until recently when more data is put on the drive (I guess it crossed the 2TB threshold?), then serious corruption occurred and both partition turned into raw.
Had I not tested it first using the external DOCK and simply put it inside, I would've realized it's only 1.5TB. (because if the drive is not partitioned, Windows reports 1.5T, same as BIOS. But if it's already partitioned as 4TB, windows will report it as 4TB, even if BIOS only says 1.5).
I would've also avoided the whole corruption episode had I simply used Windows software RAID.
Because this is an actual corruption of data due to misconfiguration, My hope for retrieving the data is not high. But nonetheless, I would like to understand more about this. If Intel controller reports drive as 1.5T, but Windows thinks it's a 4TB drive. What happens when I keep adding data to the drive past 1.5T? Does the data wrap around and overwrites the beginning of the disk? Does the data goes to where it suppose to, but now I am unable to retrieve it because the BIOS doesn't know where the data is? Or does the data simply end up in some random location in the first 1.5T space?
Is there a way I can get this data back? Is it better I attempt to retrieve the data while the drive is plugged into the intel controller, or plugged into the marvel controller that recognize it as a full 4TB drive?
I guess you can say I am done with Intel firmware RAID. Should've used Windows software RAID to begin with. I think in non RAID mode, the MB would've recognized the full capacity of the drive, like it does when I am using the external SATA port.
Moral of the story, if the BIOS and Windows reports different capacity for a drive, be very careful! Wish I had noticed this discrepancy earlier...
Few days ago, both NTFS partitions on that 4TB drive changed to 'raw' partitions, all of a sudden! I spend the entire weekend trying to recover its content (what I thought was not important, become very important when I no longer have it
and in the process, accidentally discovered what I believe to be the true cause of the corruption. Not virus, not bad drive, not corrupted OS, but because of using a 4TB drive partitioned and formatted elsewhere on the damned Intel RAID controller (that apparently doesn't properly recognize the drive and only reported 1.5T).When I installed the 4TB drive a year ago, I first tested it using my external HD dock, which apparently used the Marvel SATA controller on my MB, which is entirely separate from the internal Intel SATA/RAID controller. After 2 weeks of testing, I moved the HD inside the PC, which is using the Intel Matrix controller because I had 2 other drives in RAID1 mode.
What I did not notice is that after the switch, the BIOS only reported 1.5T, but Windows still sees it as a 4TB drive because it's already partitioned. I used it happily for over a year, until recently when more data is put on the drive (I guess it crossed the 2TB threshold?), then serious corruption occurred and both partition turned into raw.
Had I not tested it first using the external DOCK and simply put it inside, I would've realized it's only 1.5TB. (because if the drive is not partitioned, Windows reports 1.5T, same as BIOS. But if it's already partitioned as 4TB, windows will report it as 4TB, even if BIOS only says 1.5).
I would've also avoided the whole corruption episode had I simply used Windows software RAID.
Because this is an actual corruption of data due to misconfiguration, My hope for retrieving the data is not high. But nonetheless, I would like to understand more about this. If Intel controller reports drive as 1.5T, but Windows thinks it's a 4TB drive. What happens when I keep adding data to the drive past 1.5T? Does the data wrap around and overwrites the beginning of the disk? Does the data goes to where it suppose to, but now I am unable to retrieve it because the BIOS doesn't know where the data is? Or does the data simply end up in some random location in the first 1.5T space?
Is there a way I can get this data back? Is it better I attempt to retrieve the data while the drive is plugged into the intel controller, or plugged into the marvel controller that recognize it as a full 4TB drive?
I guess you can say I am done with Intel firmware RAID. Should've used Windows software RAID to begin with. I think in non RAID mode, the MB would've recognized the full capacity of the drive, like it does when I am using the external SATA port.
Moral of the story, if the BIOS and Windows reports different capacity for a drive, be very careful! Wish I had noticed this discrepancy earlier...