RAID 5 recovery

How to use TestDisk to recover lost partition
Forum rules
When asking for technical support:
- Search for posts on the same topic before posting a new question.
- Give clear, specific information in the title of your post.
- Include as many details as you can, MOST POSTS WILL GET ONLY ONE OR TWO ANSWERS.
- Post a follow up with a "Thank you" or "This worked!"
- When you learn something, use that knowledge to HELP ANOTHER USER LATER.
Before posting, please read
Posts: 2
Joined: 27 Jan 2015, 00:38

RAID 5 recovery

#1 Post by N3St »

Hi all,

I hope I did not miss a topic describing this problem, but here goes nothing.

I have an MSI z87-g45 Mobo with 3 WD HDD's in a RAID 5 configuration through Intel RST. I had to use the CMOS button due to a failed attempt at OCing and because the SATA setting went back from RAID to AHCI the controller lost track of my discs. I followed the fora and reset all of the discs to non-raid members, and afterwards I created a new RAID volume with the same settings as the previous one.

Now Testdisk recognizes my partitions if I choose the Intel partition scheme, even though Testdisk's default value is CGI EFG (or something like that). Under the latter it does not recognize everything and it says that one partition is invalid. Under the Intel partition scheme, everything looks OK, with the exception that I can't select all of the partitions to be primary partitions without Testdisk showing the "Structure: Bad" sign (see picture).

Is there anyone who has experience with this and could offer some advice on how to proceed?
Testdisk Intel Partition overview
Testdisk Intel Partition overview
TestdiskIntelPartitionview.JPG (60.68 KiB) Viewed 1984 times

User avatar
Site Admin
Posts: 5434
Joined: 18 Feb 2012, 15:08
Location: Le Perreux Sur Marne, France

Re: RAID 5 recovery

#2 Post by cgrenier »

With a PC Intel partition table, you can't exceed 4 partitions entries. One can be an extended partition that can hold several Logical partitions. In your case, you should let one partition as D(eleted) or select EFI GPT.

Posts: 2
Joined: 27 Jan 2015, 00:38

Re: RAID 5 recovery

#3 Post by N3St »

Thanks cgrenier!

In case I select EFI GPT option I run into the following two situations (I am currently not at my pc so I cannot upload a picture, but maybe the description will suffice)

- Testdisk does not recognize the right size for the lowest partition in the list (Media) and says that the found partition size exceeds the disk size. Could I be that I made an error in redefinition of the block size for the RAID array?

- Testdisk shows me several partitions more than I actually had on the array, so I am not quite sure how to proceed from there. Could I just try something out without inflicting irrecoverable damage on the MBR?

Best regards