External storage system configuration details (iSCSI)

Plan for your external storage system configurations through iSCSI connections with the system.

See the following website for the most recent support information:

www.ibm.com/support

Use the following guidelines to configure iSCSI-attached storage to the system:

  • Unlike Fibre Channel connections, you need to manually configure the connections between the source system and the target external storage systems.
  • Discovery of the target IPs and session establishment is manually configured either I/O group-wide (nodes from a specified I/O group discover and establish sessions) or system-wide (all nodes discover and establish sessions).
  • After successful discovery, initiator sessions must be established from the source system to target storage system manually through nodes in a specific I/O group or all nodes across the system.
  • A one-to-one mapping of source ports to target ports is required. The same numbered ports on each source system or node connect to only one port on each target system or node. Multiple initiator ports on the same system node cannot connect to the same target port (many-to-one connectivity). Similarly one initiator port cannot be connected to multiple target ports on same target storage system (one-to-many connectivity). The CLI command fails if such an attempt is made.
  • Zoning is not required.
  • Direct attachment between the system and external storage systems is not supported and requires Ethernet switches between the system and the external storage.
  • To avoid a single point of failure, a dual switch configuration is recommended. For full redundancy, a minimum of two paths between each initiator node and target node must be configured with each path going through a separate switch.
  • Extra paths can be configured to increase throughput if both initiator and target nodes support more ports.