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Here is the situation: Promise Array FastTrak TX4310 with 3 disks (750 GB each) in RAID5. This comes to around 1500 GB of data.

Last week I had the idea of expanding the RAID with an additional 750 GB disk. This would bring the volume to around 2250 GB. I plugged the disk and used the Webpam software to do the RAID expansion.

However, I didn't count with the MBR 2TB limit, as I didn't remembered that the disk was using MBR instead of GPT and I didn't check it prior to the expansion.

After a couple of days of expansion, today when I got home, the disk in Windows disk manager showed the message "Invalid disk" and when I try to activate it, it says "The operation is not allowed on the Invalid pack".

From what I figured, the logical volume on the RAID expanded, and passed that info to the Windows layer and I ended up with an "larger than 2TB" MBR disk.

I'm hopping that somehow I can still recover some data from this, and I was wondering if I can "rewrite" the MBR structure back to the 1500 GB partition size, so I can access the partition in Windows.

Right now I'm doing an "Analyse" with TestDisk, as I hope the program will pickup the old 1500 structure and allow me to somehow revert back to it. I think that even though the Logical Drive in the RAID is bigger than the 2TB, I can somehow correct the MBR to show the 1500 GB partition again. I had a similar problem once, and I was able to recover the data using a similar method.

What do you guys think? Is it a dead end? Am I totally screwed because there is the extra RAID layer that I'm not counting? Or is there other way to move with this?

Thanks all!

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Turns out that TestDisk didn't pick up the correct structure... Besides, one of the old disks had bad sectors, so I'm down to 3 disks, with a partition structure bigger than 2TB in MBR. I thought that perhaps I can recreate the old MBR structure "by hand", with the old CHS, disk signature and partition info... Could this be possible? – Helder Nov 15 '11 at 22:33
I was also wondering if I could "convert" the disk to GPT from MBR, even though I don't have a valid MBR structure. I'm betting on the fact that the RAID still has my data scattered around somewhere and I just need to correct the partition/disk info and get (at least some) of my data back... – Helder Nov 15 '11 at 22:42
Well, since I didn't find any info on my previous notes, I'm "biting the bullet" and switching to file recovery software... It seems that the RAID moved data around, as I can recover files, but they are garbled for the most part... Let's see what I can do... – Helder Nov 18 '11 at 15:10

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