iSCSI storage adapter rescan using a NetApp array reports 0 Targets, Devices, and Paths

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:

When adding a datastore to the ESX/ ESXi host using software iSCSI and a NetApp array, you experience these symptoms:

• iSCSI is configured correctly
• Dynamic discovery is configured properly with IP address and port 3260
• The Initiator Groups and LUNs are correctly configured on the NetApp array
• After a rescan, the iSCSI software adapter (under Storage Adapters) shows 0 for Connected Targets, Devices and Paths
• When you run the vmkiscsi-tool command to query the connected targets, you see an output similar to:
  
  [root@esx]# vmkiscsi-tool -T vmhba33

------ Target [iqn.1992-08.com.netapp:sn.135052591] info ------
NAME : iqn.1992-08.com.netapp:sn.135052591
ALIAS :
DISCOVERY METHOD FLAGS : 8
SEND TARGETS DISCOVERY SETTABLE : 0
SEND TARGETS DISCOVERY ENABLED : 0
Portal 0 : <IP1>
Portal 1 : <IP2>

  Where <IP1> is the IP address of the backup controller and <IP2> is the IP address of the primary controller.
  
  
• In the NetApp array logs, you see entries similar to:
  
  na2> iscsi initiator show
Initiators connected:
TSIH TPGroup Initiator
72 2001 iqn.1998-01.com.vmware:esx-6e9607c5 / xx:xx:xx:xx:xx:xx
73 2000 iqn.1998-01.com.vmware:esx-6e9607c5 / xx:xx:xx:xx:xx:xy
  
  
• In the ESX/ESXi host log files, you see entries similar to:
  
  2011-06-08-11:17:03: iscsid: Login Target Skipped: iqn.1992-08.com.netapp:sn.135052591 if=default addr=192.168.1.30:3260 (TPGT:2001 IS
ID:0x1) (Already Running)
2011-06-08-11:17:03: iscsid: Login Target Skipped: iqn.1992-08.com.netapp:sn.135052591 if=default addr=192.168.1.29:3260 (TPGT:2000 IS
ID:0x2) (Already Running)
2011-06-08-11:17:03: iscsid: Login Target: iqn.1992-08.com.netapp:sn.135051973 if=default addr=192.168.1.26:3260 (TPGT:2001 ISID:0x1)
2011-06-08-11:17:03: iscsid: Notice: Assigned (H33 T1 C0 session=7, target=2/3)
2011-06-08-11:17:03: iscsid: Login Target: iqn.1992-08.com.netapp:sn.135051973 if=default addr=192.168.1.25:3260 (TPGT:2000 ISID:0x2)
2011-06-08-11:17:03: iscsid: Notice: Assigned (H33 T1 C1 session=8, target=2/4)
2011-06-08-11:17:03: iscsid: DISCOVERY: Pending=2 Failed=0
2011-06-08-11:17:03: iscsid: Login Success: iqn.1992-08.com.netapp:sn.135051973 if=default addr=192.168.1.26:3260 (TPGT:2001 ISID:0x1)
2011-06-08-11:17:03: iscsid: connection 3:0 (iqn.1992-08.com.netapp:sn.135051973 if=default addr=192.168.1.26:3260 (TPGT:2001 ISID:0x1
) (T1 C0)) is operational
2011-06-08-11:17:03: iscsid: Login Success: iqn.1992-08.com.netapp:sn.135051973 if=default addr=192.168.1.25:3260 (TPGT:2000 ISID:0x2)
2011-06-08-11:17:03: iscsid: connection 4:0 (iqn.1992-08.com.netapp:sn.135051973 if=default addr=192.168.1.25:3260 (TPGT:2000 ISID:0x2
) (T1 C1)) is operational
2011-06-08-11:17:04: iscsid: DISCOVERY: Pending=0 Failed=0

Environment

VMware ESX 4.1.x
VMware ESXi 4.0.x Installable
VMware ESXi 4.1.x Installable
VMware ESXi 4.0.x Embedded
VMware ESX 4.0.x
VMware ESXi 4.1.x Embedded

Resolution

This issue occurs if there are subsequent login attempts after a proper connection has been established.

The NetApp storage system only permits one connection for each target and each initiator. Attempts to make additional connections cause the first connection to drop. Therefore, a single HBA should not attempt to connect to multiple IP addresses associated with the same NetApp target. For more information, see the VMware iSCSI SAN Configuration Guide.

To resolve this issue, check the Static Discovery tab under HBA properties for additional addresses. If there are additional addresses, remove them and then complete the wizard.

After a subsequent rescan, the targets, devices and paths get updated and you should be able to add your datastore.