raptor_pa

No it is a rule, the raid splits stuff across the each drive in equal portions. The 750 is the issue and could have broken the array pretty badly. If you create the array INITIALLY with a smaller drive, then yes it will 'downsize' the larger drives to the smallest drive, but once the array is set up, it expects to see the same size drives all the time. Hard drives don't write things to physically contiguous space, they do not start at 0 and go up by 1, they write things to where space is available, and use logically contiguous space based on rotational latency and several other factors specific to the drive. You may be able to put a matching drive in and rebuild, if that fails then you could try r-studio and have it build a virtual raid and output the data to another set of drives, then create a new array and copy your data back. If that can't rebuild it then it's probably time to seek pro recovery, not at the local computer shop or big box retail store - probably looking at $3000 or better to get your data back off the raid if you have to go that route.