Multisession

Multisessions for iSCSI hosts can be configured by using different operating systems. Several characteristics must be considered when you configure an iSCSI multisession.

The following points apply to multisession configuration:
  • The AIX® iSCSI initiator does not support multisession.
  • The use of the supported iSCSI multipathing is recommended when running the I/O with multisession.
  • If you use CHAP authentication under the Microsoft Windows operating system, use the same secret across each session that is initiated from that host to a particular target.
  • If the Microsoft Windows clustered system is rebuilt or restored from a backup, hosts must log off and then log back on to any previously connected iSCSI targets that are supplied from the system.
  • If the host application uses SCSI 3 Persistent Reservation, you must run only a single iSCSI session per node.
  • Running with multiple iSCSI sessions is not supported for applications that use Microsoft 2008 Failover clustering over an iSCSI interface. You must run only a single session per node in these situations.

For more information on session limit maximums for an iSCSI target, an I/O group, and a system, see Configuration limits.

Single subnet configurations

Some multisession configurations can support a single subnet.

Figure 1. Four two-session iSCSI multisession configurations for a single subnet
Example of four two-session iSCSI multisession configurations for a single subnet
Figure 2. Two four-session iSCSI multisession configurations for a single subnet
Example of two four-session iSCSI multisession configurations for a single subnet

Multiple and dual subnet configurations

Some multisession configurations support multiple and dual subnets.

Figure 3. Four two-session iSCSI multisession configurations for multiple subnets and dual configuration
Four two-session iSCSI multisession configurations for multiple subnets and dual configuration
Figure 4. Two four-session iSCSI multisession configurations for a multiple subnets and dual configuration
Two four-session iSCSI multisession configurations for a multiple subnets and dual configuration