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.
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 vifs). By default, each interface is in its own target portal group.
Prior to Data ONTAP 7.1, each interface was assigned to its own target portal group. The target portal group tag was assigned based on the interface location and could not be modified. This works fine for single-connection sessions.
Starting with Data ONTAP 7.1, you can explicitly create target portal groups and assign tag values. If you want to use multi-connection sessions, you need to create one or more target portal groups.
Because a session can use interfaces in only one target portal group, you may 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.
Caution
Some initiators, including those used with Windows, HP-UX, and Linux, create a persistent association between the target portal group tag value and the target. If the target portal group tag changes, the LUNs from that target will be unavailable.
When you migrate from a prior version of Data ONTAP to version 7.1, the target portal group tags will change. See the Data ONTAP 7.1 Upgrade Guide and the Data ONTAP Release Notes for information on how to migrate from an earlier release when you have iSCSI LUNs used by these operating systems.
Caution
When used with multi-connection sessions, the Windows iSCSI software initiator creates a persistent association between the target portal group tag value and the target interfaces. If the tag value changes while an iSCSI session is active, the initiator will be able to recover only one connection for a session. To recover the remaining connections, you must refresh the initiator's target information.
You can view a list of the current target portal groups using the command line or FilerView. For each target portal group, the list includes the name, tag, and the interfaces that belong to the group.
To list target portal groups, complete the following step.
| 1 |
On the storage system console, enter the following command: iscsi tpgroup show |
To list target portal groups, complete the following step.
| 1 |
If you do not plan to use multi-connection iSCSI sessions, you do not need to create target portal groups.
If you do plan to use multi-connection sessions, create a target portal group that contains all of the interfaces you want to use for one iSCSI session.
When you create a target portal group, the specified interfaces are removed from their current groups and added to the new group. Any iSCSI sessions using the specified interfaces are terminated, but the initiator should reconnect automatically. However, initiators that create a persistent association between the IP address and the target portal group will not be able to reconnect.
To create a target portal group, complete the following step.
| 1 |
On the storage system console, enter the following command: iscsi tpgroup create [-f] tpgroup_name [-t tag] -f forces the new group to be created, even if that terminates an existing session using one of the interfaces being added to the group. tpgroup_name is the name of the group being created (1 to 32 characters, no spaces or non-printing characters). -t tag sets the target portal group tag to the specified value. In general you should accept the default tag value; see About target portal groups for more information. User-specified tags must be in the range 1 to 256. interface ... is the list of interfaces to include in the group, separated by spaces. ExampleThe following command creates a target portal group named server_group that includes interfaces e8a and e9a: iscsi tpgroup create server_group e8a e9a |
To create a target portal group, complete the following steps.
| 1 | |
| 2 | |
| 3 |
Enter the Portal Group Name (1 to 32 characters, no spaces or non-printing characters). |
| 4 |
Select the interfaces to include in the group. Use Ctrl-click to select multiple interfaces. |
| 5 |
Optionally enter the User-Defined Tag. In general you should leave this field blank to accept the default tag value; see About target portal groups for more information. User-specified tags must be in the range 1 to 256. |
| 6 |
Destroying a target portal group removes the group from the storage system. Any interfaces that belonged to the group are returned to their individual default target portal groups. Any iSCSI sessions with the interfaces in the group being destroyed will be terminated.
To destroy a target portal group, complete the following step.
To destroy a target portal group, complete the following steps.
| 1 | |
| 2 |
Select the Portal Group. Note that you cannot destroy the default target portal groups. |
| 3 |
You can add interfaces to an existing target portal group. The specified interfaces are removed from their current groups and added to the new group. Any iSCSI sessions using the specified interfaces are terminated, but the initiator should reconnect automatically. However, initiators that create a persistent association between the IP address and the target portal group will not be able to reconnect.
To add one or more interfaces to an existing target portal group, complete the following step.
To add one or more interfaces to an existing target portal group, complete the following steps.
You can remove interfaces from an existing target portal group. The specified interfaces are removed from the group and returned to their individual default target portal groups. Any iSCSI sessions with the interfaces being removed are terminated, but the initiator should reconnect automatically. However, initiators that create a persistent association between the IP address and the target portal group will not be able to reconnect.
To remove one or more interfaces from an existing target portal group, complete the following step.
To remove one or more interfaces from an existing target portal group, complete the following steps.
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Part No. 210-01094_B0
File: c11mgt-7.htm
Last updated: 08-Dec-2005 13:25:39