Changes for Data ONTAP 7.1

Administration model changes

In Data ONTAP 7.1, the administrative model for managing iSCSI networks has changed. If you have used iSCSI with earlier versions of Data ONTAP, you should pay special attention to this section and to Management changes for iSCSI in Data ONTAP 7.1.

In earlier releases of Data ONTAP, you managed the iSCSI software target driver using the iswt command. In Data ONTAP 7.1, you do not need to manage the iswt driver. Instead, you manage the iSCSI service using FilerView or the iscsi command. You manage the underlying networking interfaces using the standard networking commands or FilerView pages.

Target portal group changes

In earlier releases, each interface (Ethernet port or vif) was in its own target portal group and there was no way to change this. In Data ONTAP 7.1, a portal group can contain multiple interfaces. This change is required to support multi-connection sessions. Each iSCSI session between an initiator and target can have more than one underlying TCP connection.

Multi-connection session changes

Data ONTAP 7.1 supports multi-connection sessions. An iSCSI session between an initiator and the storage system can use as many as 16 TCP/IP connections. By default, this feature is turned off and only one TCP/IP connection is allowed for each session. See Enabling multi-connection sessions.

Error recovery level changes

The iSCSI specification (RFC 3720) defines three error recovery levels: 0, 1, and 2. The specification requires initiators and targets to support level 0; the other two levels are optional. With ErrorRecoveryLevel=0, whenever a problem is detected in an iSCSI session, the session is typically dropped and then reestablished. Levels 1 and 2 enable more sophisticated error detection and recovery.

Data ONTAP 7.1 can support all three error recovery levels; earlier versions supported only level 0.

By default, the storage system allows only error recovery level 0. See Enabling error recovery levels 1 and 2.