4100+ : 2 disk RAID 1 -> 4 disk RAID 5

[JayBird]

Can i go from a 2 disk RAID 1 to a 4 disk RAID 5 leaving my data intact? or do i need to remove my data first!?

If so, what would the process be?

Thanks

[SiM]

Well they usually recommend that you back up regardless. But if the device supports raid migration (check this!) then you should be able to upgrade disks and raid level without losing all data, but it can take a long time to rebuild the array.