I recently had some issue with my NTFS partition that led to my NTFS boot sector to get corrupted.
The partition is very large (~6TB) and consists of 4xSamsung F4EG 2TB in Raid5 connected to Perc 6/i Raid controller.
When the partition is lost, I can repair it using testidsk in the following way.
When I enter Windows (W7 x64) Disk Mangament, I get a wizard and then I init the drive to GPT.
I then convert it to a basic volume, assign a letter but do not format it.
At this point, the partition is at the right size but set to "RAW".
Now I run testdisk, choose the drive, select [EFI GPT] ->[Advanced], I get 2 options:
Disk /dev/sdb - 5999 GB / 5587 GiB - CHS 729401 255 63
Partition Start End Size in sectors
1 P MS Reserved 34 262177 262144 [Microsoft reserved partition]
> 2 P MS Data 264192 11717834751 11717570560 [Basic data partition] [Data]
I choose "2 P Ms Data", then select Type->Ms Data->NTFS.
Now I go to Boot menu and see that "Boot Sector" is bad and "Backup boot sector" is good and I choose to load the Backup boot sector instead of the main one.
After a few seconds, the partition is back and recognized as NTFS and all is good.
The weird thing is that somehow it keeps getting back to that corrupted state and I don't know how or why


My array is healthy, I ran disk check and didn't find any issues so I am kind of out of ideas right now.
Any ideas ?