I have a dead La Cie Big disk terabyte external drive. It won't mount and it isn't recoverable the way it is. So I looked inside, it's 2 x 500 gig Seagate drives. So, I took the 2 drives out and installed one of them in a Mac Pro to see if it would mount on it's own. I figured probably not, since there were two drives mounted in this La Cie external case, they must have been RAID-ed together. I don't really know much about RAID, obviously. Disk utility saw the disk, but it wouldn't mount and gave the unreadable message. Tried to disk utility it, and it gave file system errors, not surprised. It looks like you can't separate them, the RAID must split the files onto the two disks. Is there any point to trying the utility Data Recovery on it? Or should I just tell my boss the only way to get the data back is to send it out to a data recovery place? I don't want to try and reformat them if there is still any possible way to get the data off them. I think the drives are fine and would work as a terabyte drive in the Fantom case if reformatted, but then we lose all these important projects. Any advice would be greatly appreciated. We seem to have the worst luck with external hard drives. The odd thing is that I have another dead terabyte drive, a Fantom drive in which one of the 500 gig drives started clicking. I took both 500 gig WD drives out of the Fantom case and installed the two Seagate 500s from the dead La Cie case. It shows up in Disk Utility as an unformatted 1T drive. I was hoping it might just reconstitute itself in another case, but no go. If worse comes to worse, I will reformat it and it will probably be useable.