Node configuration details

Apply these configuration details to IBM Spectrum Virtualize™ nodes to ensure that you have a valid configuration.

Host bus adapters and nodes

IBM Spectrum Virtualize nodes contain a mix of different supported network adapters. For specific information on what the system supports, see the optional features topic.

Volumes

Each node presents a volume to the SAN through Fibre Channel ports or iSCSI ports. Each volume is accessible from the two nodes in an I/O group. Each HBA port can recognize up to eight paths to each logical unit (LU) that is presented by the clustered system. The hosts must run a multi-pathing device driver before the multiple paths can resolve to a single device. You can use fabric zoning to reduce the number of paths to a volume that are visible by the host.

Optical connections

Valid optical connections are based on the fabric rules that the manufacturers impose for the following connection methods:

Host to a switch
Back end to a switch
Inter-switch links (ISLs)

Optical fiber connections can be used between a node and its switches.

Systems that use the intersystem Metro Mirror and Global Mirror feature can use optical fiber connections between the switches, or they can use distance-extender technology that is supported by the switch manufacturer.

Ethernet connection

To ensure system failover operations, Ethernet port 1 on all nodes must be connected to the same set of subnets. If used, Ethernet port 2 on all nodes must also be connected to the same set of subnets. However, the subnets for Ethernet port 1 do not have to be the same as Ethernet port 2.

Fibre Channel connection

IBM Spectrum Virtualize supports shortwave and longwave Fibre Channel connections between IBM Spectrum Virtualize nodes and the switches that they are connected to.

To avoid communication between nodes that route across interswitch links (ISLs), connect all IBM Spectrum Virtualize nodes to the same Fibre Channel or FCF switches.

No ISL hops are permitted among the IBM Spectrum Virtualize nodes within the same I/O group. However, no more than three ISL hops are permitted among IBM Spectrum Virtualize nodes that are in the same system though different I/O groups. If your configuration requires more than three ISL hops for IBM Spectrum Virtualize nodes that are in the same system but in different I/O groups, contact your IBM® service representative.

To avoid communication between nodes and storage systems that are being routed across ISLs, connect all storage systems to the same Fibre Channel switches as the IBM Spectrum Virtualize nodes. One ISL hop between the IBM Spectrum Virtualize nodes and the storage controllers is permitted. If your configuration requires more than one ISL, contact your IBM service representative.

Avoid communication between nodes and storage systems that are being routed across ISLs. To do so, connect all storage systems to the same Fibre Channel or FCF switches as the IBM Spectrum Virtualize nodes. One ISL hop between the IBM Spectrum Virtualize nodes and the storage systems is permitted. If your configuration requires more than one ISL, contact your IBM service representative.

In larger configurations, it is common to have ISLs between host systems and the IBM Spectrum Virtualize nodes.

Port speed

Fibre Channel ports on IBM Spectrum Virtualize nodes can operate at 16 Gbps, 8 Gbps, and 4 Gbps. The ports are not supported on 2 Gbps speed switches.