NetApp
Configuration : Protocols > iSCSI : Understanding iSCSI : Target portal group management
Target portal group management
A target portal group is a set of one or more storage system network interfaces that can be used for an iSCSI session between an initiator and a target. A target portal group is identified by a name and a numeric tag. If you want to have multiple connections per session across more than one interface for performance and reliability reasons, then you must use target portal groups.
Note: If you are using MultiStore, you can also configure non-default vFiler units for target portal group management based on IP address.
For iSCSI sessions that use multiple connections, all of the connections must use interfaces in the same target portal group. Each interface belongs to one and only one target portal group. Interfaces can be physical interfaces or logical interfaces (VLANs and interface groups).
Prior to Data ONTAP 7.1, each interface was automatically assigned to its own target portal group when the interface was added. The target portal group tag was assigned based on the interface location and could not be modified. This works fine for single-connection sessions.
You can explicitly create target portal groups and assign tag values. If you want to increase performance and reliability by using multi-connections per session across more than one interface, you must create one or more target portal groups.
Because a session can use interfaces in only one target portal group, you might want to put all of your interfaces in one large group. However, some initiators are also limited to one session with a given target portal group. To support multipath I/O (MPIO), you need to have one session per path, and therefore more than one target portal group.
When an interface is added to the storage system, each network interface is automatically assigned to its own target portal group.
In addition, some storage systems support the use of an iSCSI Target expansion adapter, which contains special network interfaces that offload part of the iSCSI protocol processing. You cannot combine these iSCSI hardware-accelerated interfaces with standard iSCSI storage system interfaces in the same target portal group.

Was this topic helpful? Send comments to NetApp.