Target Discovery Methods

Language:

The three target discovery methods available in Oracle Solaris are as follows:

sendtargets discovery method
Internet Storage Name Service (iSNS) discovery method
Static discovery method

Note - Do not configure an iSCSI target to be discovered by more than one discovery method.

The following sections describe how to configure these device discovery methods.

Administering `sendtargets` Discovery Method

sendtargets is one of the dynamic target discovery methods. This is a simple discovery method to configure an iSCSI initiator to connect to all the targets on a particular storage device.

To enable an iSCSI initiator to use the sendtargets discovery method, you must specify the IP address and port number of the iSCSI target node. The target node sends the list of all available targets and portals to the initiator. After receiving the target and portal information, the initiator tries to establish sessions with all of those targets through all the portals.

If the initiator does not have access to all the target portals or if you do not want the initiator to establish sessions with all available targets then, use Static configuration or iSNS discovery method.

How to Configure `sendtargets` Discovery Method

Become an administrator.
For more information, see Using Your Assigned Administrative Rights in Securing Users and Processes in Oracle Solaris 11.4.

Verify that the iSCSI initiator service is online.

initiator# svcs network/iscsi/initiator
STATE          STIME    FMRI
online         17:33:28 svc:/network/iscsi/initiator:default

Obtain the target IP address and port number from the iSCSI storage device management interface.
For more information about how to retrieve this information, see the specific storage device vendor documentation.
To configure the sendtargets discovery method, provide the discovery address:
```
initiator# iscsiadm add discovery-address 192.0.2.10
```
If no port number is provided, the default port 3260 is used.

Review the sendtargets configuration information.

initiator# iscsiadm list target
Target: iqn.1986-03.com.sun:02:02380f80-ab3c-47a9-8882-d3cafc2c49ae
        Alias: -
        ISID: 4000002a0000
        Connections: 0
Target: iqn.1986-03.com.sun:02:3b8eb56d-051a-43ef-b56e-d2b81c94959b
        Alias: -
        ISID: 4000002a0000
        Connections: 0

You can also use the iscsiadm list target -v command for information about the targets.

Enable the sendtargets discovery method.
```
initiator# iscsiadm modify discovery --sendtargets enable
```
To list the discovered targets see, Displaying iSCSI Configuration. For more information about the iscsiadm command, see the iscsiadm(8) man page.

Administering Internet Storage Name Service Target Discovery Method

The Internet Storage Name Service (iSNS) enables an iSCSI initiator to discover the targets to which it has access, by using as little configuration information as possible. It also provides state change notifications to notify an iSCSI initiator when there are changes in the operational state of storage nodes. To use the iSNS discovery method, you must provide the iSNS server address and port number combination. This enables the iSCSI initiator to query the iSNS server that you specified to perform the device discovery. The default port for the iSNS server is 3205.

The iSNS discovery method is suitable for large iSCSI setup with multiple iSCSI initiator hosts or multiple iSCSI target nodes or when state change notifications are required. iSNS provides similar functionality as FC fabric services.

For more information about setting up iSNS support in Oracle Solaris, see Chapter 9, Configuring and Managing the Oracle Solaris Internet Storage Name Service (iSNS) in Managing Devices in Oracle Solaris 11.4.

How to Configure Internet Storage Name Service Target Discovery Method

Become an administrator.
For more information, see Using Your Assigned Administrative Rights in Securing Users and Processes in Oracle Solaris 11.4.

Verify that the iSCSI initiator service is online.

initiator# svcs network/iscsi/initiator
STATE          STIME    FMRI
online         17:33:28 svc:/network/iscsi/initiator:default

Obtain the target IP address and port number from the iSNS server management interface.
If you are using the Oracle iSNS server, see Chapter 9, Configuring and Managing the Oracle Solaris Internet Storage Name Service (iSNS) in Managing Devices in Oracle Solaris 11.4.

If you are using a third-party iSNS server, see the specific vendor documentation.
Configure the iSNS discovery method by providing the IP address of the iSNS server.
```
initiator# iscsiadm add isns-server 198.51.100.2
```

Review the iSNS configuration information.

initiator# iscsiadm list isns-server -v
iSNS Server IP Address: 203.0.113.66/27:3205

Enable the iSNS discovery method.
```
initiator# iscsiadm modify discovery --iSNS enable
```
To list the discovered targets, see Displaying iSCSI Configuration.

Administering Static Configuration Discovery Method

You can use the static configuration discovery method in the followings scenarios:

When only a few iSCSI targets must be discovered.
To restrict the initiator to access only a specific number of targets presented by the sendtargets discovery.
When the initiator must not access all the target portals of the storage device.

You can determine the static target address from the management tool of the array. For more information, see the iscsiadm(8) man page.

Note - Do not configure an iSCSI target to be discovered by both static and dynamic device discovery methods. Usage of redundant discovery methods reduces the performance, when an initiator is communicating with iSCSI target devices.

How to Configure an iSCSI Initiator With Static Configuration

Become an administrator.
For more information, see Using Your Assigned Administrative Rights in Securing Users and Processes in Oracle Solaris 11.4.

Verify that the iSCSI initiator service is online.

initiator# svcs network/iscsi/initiator
STATE          STIME    FMRI
online         17:33:28 svc:/network/iscsi/initiator:default

Obtain the target IP address and iSCSI target name from the iSCSI storage device management interface.
For more information about how to retrieve this information, see the specific vendor documentation.

Configure the target to be statically discovered.

initiator# iscsiadm add static-config target-name,target-address[:port-number][,tpgt]

For example:

initiator# iscsiadm add static-config iqn.1986-03.com.sun:02:73d12edc-9bb9-cb44-efc4-c3b36c123456, 192.0.2.2:3260

For more information, see the iscsiadm(8) man page.

Review the static configuration information.

initiator# iscsiadm list static-config
Static Configuration Target: iqn.1986-03.com.sun:02:73d12edc-9bb9-cb44-efc4-c3b36c123456,
192.0.2.2:3260

The iSCSI connection is not initiated until the discovery method is enabled.

Enable the static configuration discovery method.
```
initiator# iscsiadm modify discovery --static enable
```
To list the discovered targets, see Displaying iSCSI Configuration.

Managing SAN Devices and I/O Multipathing in Oracle® Solaris 11.4