IBM DS8000 - Manual (Page 200)

178 DS8000 Series: Concepts and Architecture
Figure 9-10 Sparing example 2: RAID-10 - All same capacity, same RPM
In Figure 9-10, four RAID-10 arrays are installed in a DA pair. Two arrays need two spare disk
drives (3x2+2S). One spare disk is in one loop and other spare disk is in the other loop in an
array. The other two arrays don’t need spare disks (4x2).
If you add other arrays configured with the same capacity and RPM as in this DA pair,
additional arrays don’t need spare disks (the arrays will be configured as RAID-5:7+P,
RAID-10:4x2).
Sparing Example 2 – RAID-10:
All same capacity, same RPM
• Assumes all devices same capacity & same RPM
• Minimum of 4 spares per DA pair
– 2 spares per loop & 2 spares in each array group
– Additional RAID-10 arrays will be 4x2
– Any additional RAID-5 arrays will 7 + P
• All spares available to all arrays on DA pair
1
2
3
4
DA DA
…
…
3x2 + 2S
Array 4x2
Array 4x2
Array 3x2 + 2S
Array