iSCSI support

Be aware of the following general iSCSI support considerations.

The general iSCSI parameters are applicable regardless of the operating system.

• The system supports:
  • The standard iSCSI port (3260)
  • A maximum of 512 hosts per I/O group. Only 256 hosts can be configured as iSCSI, due to IQN limits.
  • A maximum of 512 hosts per I/O group.
  • A maximum of 512 hosts per I/O group for all supported node types.
  • Up to 1024 sessions per system iSCSI target from different iSCSI hosts. A maximum of 2048 sessions per I/O group from iSCSI hosts with up to four sessions from one iSCSI host to each system iSCSI target.
  • I/O from Fibre Channel and iSCSI initiators in different hosts to the same volumes
    Note: The system does not support I/O from Fibre Channel and iSCSI initiators in the same hosts to the same volumes.
  • Multiple sessions from iSCSI hosts, with a maximum of four sessions from one iSCSI host to each system iSCSI target
  • BI-CHAP authentication with initiators that accept a blank user name field
  • I/O from different initiators in the same host to the same I/O group
  • I/O from different initiators in different hosts to the same volumes
  • Both the iSNS Protocol (allowing iSCSI initiators to locate appropriate storage resources that use the Internet Storage Name Service) and CHAP-based authentication (associating iSCSI authentication information with a host object)
  • iSCSI host attachment, with each node that acts as an iSCSI target
• iSCSI uses either iSCSI qualified name (IQN) (223 bytes) or extended unique identifier (EUI) (64-bit) names.
  Note: Ensure that the IP takeover facility in an I/O group is enabled. Then, if the node that is acting as the iSCSI target fails, the partner node takes over the IP addresses of the failed node, thus continuing operations. During takeover, the iSCSI initiator is logged out from the failed node. A new session or login is re-established with the partner (working) node that uses the IP address of the failed node.
• Both 1 GB and 10 GB Ethernet ports can be used for iSCSI traffic, but only the 1 GB Ethernet ports can be used for management traffic.
• Each iSCSI target can support both IPv4 and IPv6 concurrently.
• Volumes are mapped to a host that uses the same host mapping mechanism as Fibre Channel attachment. A volume can be mapped to a Fibre Channel host or an iSCSI host. Mapping a volume through both iSCSI and Fibre Channel to the same host is not supported.
• All IP addresses (service and configuration) associated with a clustered-system Ethernet port must be on the same subnet. However, IP addresses associated with a node Ethernet port used for iSCSI traffic can be configured to belong to different subnets.