RAID5 and RAID6 disk mirroring provide highly secure data protection. you can use hard drives of the same capacity to create a RAID array. The RAID creates an exact copy of the data on the member drives to protect your data against a drive failure. With RAID5, if one drive fails you can hot-swap it for a new drive, with no downtime. With RAID6, up to two drives can fail with no downtime.
This short video explains how to hot swap the hard drives on a Cisco Smart Storage device.