The most painful thing in a RAID technology is its super-lengthy rebuild process. Disk manufacturers are packing lots of storage capacity per disk. They are now producing an extra-large capacity of disk drives at a fraction of the price. We no longer talk about 450 GB, 600 GB, or even 1 TB disks, as there is a larger capacity of disks available today. The newer enterprise disk specification offers disks up to 4 TB, 6 TB, and even 10 TB disk drives, and the capacities keep increasing year by year.

Think of an enterprise RAID-based storage system that is made up of numerous 4 TB or 6 TB disk drives. Unfortunately, when such a disk drive fails, RAID will take several hours and even up to days to repair a single failed disk. Meanwhile, if another drive fails from the same RAID group, then it would become a chaotic situation. Repairing multiple large disk drives using RAID is a cumbersome process.