Why is the initial disk configuration of my AFF A70 set up in a specific pattern
Applies to
- AFF A70
- AFF A800
- ONTAP 9
- Initial setup and disk configuration
Answer
- The AFF A70 system is designed with a backplane divided into four quadrants, each connected to one of the four PCI switches on the motherboard.
- The initial disk configuration is optimized to distribute the workload evenly across these quadrants, ensuring optimal performance.
- Here is the detailed breakdown:
- Disks 0-11: Connected to PCI Switch 1
- Disks 12-23: Connected to PCI Switch 2
- Disks 24-35: Connected to PCI Switch 3
- Disks 36-47: Connected to PCI Switch 4
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The current configuration spreads the workload across all four quadrants, which helps in optimizing performance.
-
Changing the disk configuration to group all disks together, as suggested in your example, would concentrate the load on PCI Switches 1 and 2, leaving PCI Switches 3 and 4 underutilized.
-
This imbalance can lead to performance degradation and is not recommended.
Example of current configuraiton:
0, 1, 2, x, x, x, 6, 7, x, x, x, x, 12, 13, 14, x, x, x, 18, 19
24, 25, 26, x, x, x, 30, 31, x, x, x, x, 36, 37, 38, x, x, x, 42, 43
Proposed configuration (not recommended):
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, x, x, x, x
x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x
- For optimal performance, it is recommended to follow the initial configuration and add disks according to the guidelines provided in the Hardware Universe documentation.
- This ensures that the workload remains balanced across all PCI switches.
Additional Information