Is it possible, in theory, increase the size of the RAID-array of any level just by adding new drive(s)? Variant like "backup whole data - delete old array - add/replace disks - create new array - restore data" is obvious so what are the other options? Does it depend on the RAID-level only or on the implementation of RAID-controller only, or on both? Adding new disks to a striped array necessarily leads to a rebuilding of the array with the redistribution of the strips to the new drives? What steps should be done to increase size of RAID-array in online/offline scenarios? Especially interesting RAID-5 and RAID-10. I would like to see the big picture.