**RAID-1 Overheads**(treating RAID-1 and RAID-10 as identical)

N = number of drives mirrored. N=2 for duplicated

G = number of drive-sets in a Volume Group.

\(N \times G\) is the total number of drives in Volume Group.

An array may be composed of many Volume Groups.

*Per-Disk:*

- Effective Capacity
- N=2. \( 1 \div 2 = 50\% \) [duplcated]
- N=3. \(1 \div 3 = 33.3\% \) [triplicated]

- I/O Overheads & scaling
- Capacity Scaling: linear to
*max disks*. - Random
*Read*: \(N \times G \rm\ of\ rawdisk = N \times G \rm\ singledrive = RAID-0\) - Randdom
*Write*: \(1 \times G \rm\ of\ rawdisk = 100\% \rm\ singledrive\) - Streaming
*Read*: \(N \times G \rm\ of\ rawdisk = N \times G \rm\ singledrive = RAID-0\) - Streaming
*Write*: \(1 \times G \rm\ of\ rawdisk = 100\% \rm\ singledrive\)