Troubleshooting common iSCSI problems

LUNs are not visible on the host

The iSCSI LUNs appear as local disks to the host. If the storage system LUNs are not available as disks on the hosts, verify the following configuration settings.

Configuration setting	What to do
Cabling	Verify that the cables between the host and the storage system are properly connected.
Network connectivity	Verify that there is TCP/IP connectivity between the host and the storage system. From the storage system command line, ping the host interfaces that are being used for iSCSI. From the host command line, ping the storage system interfaces that are being used for iSCSI.
System requirements	Verify that the components of your configuration are qualified by NetApp. Verify that you have the correct host operating system (OS) service pack level, initiator version, Data ONTAP version, and other system requirements. You can check the most up to date system requirements in the NetApp iSCSI Support Matrix at the following URL: http://now.netapp.com/NOW/knowledge/docs/san/fcp_iscsi_config/ iscsi_support_matrix.shtml
Jumbo frames	If you are using jumbo frames in your configuration, ensure that jumbo frames are enabled on all devices in the network path: the host Ethernet NIC, the storage system, and any switches.
iSCSI service status	Verify that the iSCSI service is licensed and started on the storage system according to the procedure described in Managing the iSCSI service.
Initiator login	Verify that the initiator is logged in to the storage system. See Displaying initiators connected to the storage system. If the command output shows no initiators are logged in, check the initiator configuration on the host. Verify that the storage system is configured as a target of the initiator.
iSCSI node names	Verify that you are using the correct initiator node names in the igroup configuration. For the storage system, see Managing igroups. On the host, use the initiator tools and commands to display the initiator node name. The initiator node names configured in the igroup and on the host must match.
LUN mappings	Verify that the LUNs are mapped to an igroup. On the storage system console, use one of the following commands: `lun show -m`--Displays all LUNs and the igroups they are mapped to. `lun show -g` igroup-name--Displays the LUNs mapped to a specific igroup. Or, using FilerView, Click LUNs > Manage--Displays all LUNs and the igroups that are mapped to. For more information, see Creating LUNs, igroups, and LUN maps.

Storage system cannot register with iSNS server

Different iSNS server versions follow different draft levels of the iSNS specification. If there is a mismatch between the iSNS draft version used by the storage system and by the iSNS server, the storage system will not be able to register.

For more information, see Resolving iSNS service version incompatibility.

No multi-connection session

All of the connections in a multi-connection iSCSI session must go to interfaces on the storage system that are in the same target portal group. If an initiator is unable to establish a multi-connection session, check the portal group assignments of the initiator. For more information, see Managing target portal groups.

If an initiator can establish an multi-connection session, but not during a cluster failover (CFO), the target portal group assignment on the partner storage system is probably different from the target portal group assignment on the primary storage system. For more information, see Requirements for clustered iSCSI systems.

Sessions constantly connecting and disconnecting during CFO takeover

An iSCSI initiator that uses multipath I/O will constantly connect and disconnect from the target during cluster failover (CFO) if the target portal group is not configured correctly. The interfaces on the partner storage system must have the same target portal group tags as the interfaces on the primary storage system. For more information, see Requirements for clustered iSCSI systems.

Storage system iSCSI error messages

The following section describes some common iSCSI error messages, explanations of these messages, and what to do.

Message	Explanation	What to do
`ISCSI: Incorrect iSCSI configuration file version`	If you upgrade from Data ONTAP 6.4.x and you have CHAP authentication configured, the CHAP configuration from the previous release is not saved. The CHAP configuration file in Data ONTAP 6.5 uses a new format that is not compatible with the CHAP configuration file format of the previous release.	Use the `iscsi security` command to reconfigure CHAP settings. For detailed information, see Managing security for iSCSI initiators.
ISCSI: network interface identifier disabled for use; incoming connection discarded	The iSCSI service is not enabled on the interface.	Use the `iscsi` command or FilerView LUNs > iSCSI > Manage Interfaces page to enable the iSCSI service on the interface. Example iscsi interface enable e9b
ISCSI: Authentication failed for initiator nodename	CHAP is not configured correctly for the specified initiator.	Check CHAP settings. Inbound credentials on the storage system must match outbound credentials on the initiator. Outbound credentials on the storage system must match inbound credentials on the initiator. You cannot use the same user name and password for inbound and outbound settings on the storage system. For detailed information, see Managing security for iSCSI initiators

Message

Explanation

What to do

ISCSI: Incorrect iSCSI 
configuration file 
version

If you upgrade from Data ONTAP 6.4.x and you have CHAP authentication configured, the CHAP configuration from the previous release is not saved. The CHAP configuration file in Data ONTAP 6.5 uses a new format that is not compatible with the CHAP configuration file format of the previous release.

Use the iscsi security command to reconfigure CHAP settings. For detailed information, see Managing security for iSCSI initiators.

ISCSI: network 
interface identifier 
disabled for use; 
incoming connection 
discarded

The iSCSI service is not enabled on the interface.

Use the iscsi command or FilerView LUNs > iSCSI > Manage Interfaces page to enable the iSCSI service on the interface.

Example

iscsi interface enable e9b

ISCSI: Authentication 
failed for initiator 
nodename

CHAP is not configured correctly for the specified initiator.

Check CHAP settings.

Inbound credentials on the storage system must match outbound credentials on the initiator.
Outbound credentials on the storage system must match inbound credentials on the initiator.
You cannot use the same user name and password for inbound and outbound settings on the storage system.

For detailed information, see Managing security for iSCSI initiators