How to Configure iSCSI Target Ports

The COMSTAR iSCSI port provider implements the iSCSI transport known as iscsit. The iscsit transport runs as a service (svc:/network/iscsi/target). You must enable iscsit for it to be recognized by STMF.

The OpenSolaris software (SXCE Build 103) contains another iSCSI target implementation known as the iSCSI target daemon that is controlled by the SMF service (svc:/system/iscsitgt:default). The iSCSI target daemon is used by iSCSI targets that run on Solaris 10, Nevada, Solaris Express Community Edition, and other OpenSolaris distributions. The iSCSI transport (iscsit) and the iSCSI target daemon (iscsitgtd) are not compatible with one another.

The following packages are required and you should install them before you configure the iSCSI target.

SUNWiscsitu
SUNWiscsitr
SUNWiscsidmu
SUNWiscsidmr
SUNWstmf
SUNWstmfu

Important Note
Due to the incompatibility between iscsit and iscsitgtd, you must decide which iSCSI target service to implement. Only one of these services can be active at a time. The other service must be disabled.

iSCSI Targets

The itadm command manages iSCSI targets within the SCSI Target Mode Framework (STMF). This method allows iSCSI initiators to access STMF logical units using the iSCSI protocol. STMF treats iSCSI targets as local ports. You can then map logical units to iSCSI targets using the stmfadm command.

An iSCSI target is an access point to STMF logical units, and has no backing store associated with it directly. You can use one iSCSI target to access all STMF logical units. However, you might want to create targets for specific configurations, such as a target portal group that restricts traffic to specific network interface cards (NICs).

iSER Targets and Initiators

The iSCSI Extensions for RDMA (iSER) protocol accelerates the iSCSI protocol by mapping data transfers to remote direct memory access (RDMA) operations. As a result, an iSER initiator can read and write data from an iSER target at high data rates, with relatively low CPU utilization compared to iSCSI using TCP/IP. An InfiniBand Host Channel Adapter (HCA) is required to use iSER. For hosts with an InfiniBand-switched fabric communications link, you must configure IPoIB for the HCAs on both initiators and targets so they can communicate using IP. If an initiator can establish an InfiniBand reliable connected (RC) connection with the target, the initiator will automatically select iSER transport. The iSER protocol is not currently available on Ethernet networks.

How to Verify and Disable Active iSCSI Target Services

Use this procedure to determine whether an iSCSI service is running on your system. If iscsitgtd is running, disable it before continuing with configuring an iSCSI port for use with COMSTAR.

Log in to the target device and search for iSCSI services that are active.
```
svcs -a | grep -i iscsi
```

If iscsitgt is active, disable it.

# svcs iscsitgt

STATE            TIME                FMRI
online            14:20:11        svc:/system/iscsitgt:default

svcadm disable iscsitgt

How to Configure an iSCSI Target Port

This procedure configures an iSCSI target port through which an iSCSI initiator will be able to access a SCSI logical unit.

Enable the iscsit service.

# svcadm enable -r svc:/network/iscsi/target:default

Verify that the service is enabled.

# svcs -a | grep iscsi

online  14:21:25 svc:/network/iscsi/target:default

Create an iSCSI target port.

# itadm create-target

Target: iqn.1986-03.com.sun:02:97c1caa8-5732-ec53-b7a2-a722a946fead
successfully created

Verify that the target exists and make a note of the target name.

# itadm list-target

TARGET NAME                                                  STATE   SESSIONS
iqn.1986-03.com.sun:02:97c1caa8-5732-ec53-b7a2-a722a946fead  online  0

Where to Go Next

How to Configure an iSCSI Target for Discovery

How to Configure iSCSI Target Ports