Installation guide

Scanning iSCSI Interconnects

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However, if the targets do not send an iSCSI async event, you need to manually scan them using the

iscsiadm utility. Before doing so, however, you need to first retrieve the proper --targetname and

the --portal values. If your device model supports only a single logical unit and portal per target,

use iscsiadm to issue a sendtargets command to the host, as in:

iscsiadm -m discovery -t sendtargets -p target_IP:port

The output will appear in the following format:

target_IP:port,target_portal_group_tag proper_target_name

For example, on a target with a proper_target_name of

iqn.1992-08.com.netapp:sn.33615311 and a target_IP:port of 10.15.85.19:3260, the

output may appear as:

10.15.84.19:3260,2 iqn.1992-08.com.netapp:sn.33615311

10.15.85.19:3260,3 iqn.1992-08.com.netapp:sn.33615311

In this example, the target has two portals, each using target_ip:ports of 10.15.84.19:3260

and 10.15.85.19:3260.

To see which iface configuration will be used for each session, add the -P 1 option. This option will

print also session information in tree format, as in:

Target: proper_target_name

Portal: target_IP:port,target_portal_group_tag

Iface Name: iface_name

For example, with iscsiadm -m discovery -t sendtargets -p 10.15.85.19:3260 -P 1,

the output may appear as:

Target: iqn.1992-08.com.netapp:sn.33615311

Portal: 10.15.84.19:3260,2

Iface Name: iface2

Portal: 10.15.85.19:3260,3

Iface Name: iface2

This means that the target iqn.1992-08.com.netapp:sn.33615311 will use iface2 as its

iface configuration.

With some device models (e.g. from EMC and Netapp), however, a single target may have multiple

logical units and/or portals. In this case, issue a sendtargets command to the host first to find new

portals on the target. Then, rescan the existing sessions using:

iscsiadm -m session --rescan

You can also rescan a specific session by specifying the session's SID value, as in:

iscsiadm -m session -r SID --rescan

For information on how to retrieve a session's SID value, refer to Section 21.2.1, “iSCSI API”.