Example Of Recommended Switch Subnets - IBM FlashSystem A9000R Deployment Manual

v Default gateway
v Maximum transmission unit (MTU)
Notes:
1. If two or more iSCSI connections exist in your iSCSI network, iSCSI ports for
2. MTU configuration is required if the network supports an MTU that is greater
3. Because the FlashSystem A9000R system acts as a TCP server for iSCSI
4. If present, Ethernet VLANs and IP routers must be configured to enable
5. If present, IP routers must be configured to enable access between the hosts
Important: Link aggregation is not supported. Ports cannot be bonded.
For supported interoperability configurations, see the System Storage
Interoperation Center website (www.ibm.com/systems/support/storage/config/
ssic).
iSCSI best practices
Talk to your IBM planning representative (IPR) to help optimally setup your host
connections, according to your needs.
In order to achieve high performance, it is important to:
1. Spread the host connections to each grid controller evenly.
2. Utilize the CPU in each grid controller as much as possible; therefore, it is
It is recommended to use half the ports in each grid controller (ports 1 and 4) and
create three identical subnets in each switch.
Table 25 is an example of how the subnets should be divided in a full rack
configuration.
This configuration creates high availability, high performance, and balancing. In
addition, all grid controllers are utilized for each host.
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IBM FlashSystem A9000R Models 9835-415 and 9837-415 Deployment Guide
mirroring must be defined on switches with Flow Control Send On.
than the default 1536 bytes.
The maximum MTU value supported is 9216 bytes.
connections, packets are always routed through the Ethernet port from which
the iSCSI connection was initiated. The default gateways are required only if
the hosts are not on the same layer-2 subnet as the FlashSystem A9000R
system.
connectivity between the host systems and the FlashSystem A9000R system.
and the FlashSystem A9000R system.
recommended to use ports 1 and 4 and then ports 2 and 3.
Table 25. Example of recommended switch subnets
Switches Subnet Grid controllers
1, 2 1 Grid controllers 1, 2, 3, 4
1, 2 2 Grid controllers 5, 6, 7, 8
1, 2 3 Grid controllers 9, 10, 11, 12
Port numbers
1, 4
1, 4
1, 4