Incompliance of the Emulex LPe12002 HBA with the FC Protocol Led to Possible Failures to Set Up a Connection

Publication Date:  2012-07-19 Views:  575 Downloads:  0
Issue Description

Product and version information:

  • S5500T V100R001 V100R002
  • S5600T V100R001 V100R002
  • S6800T V100R001 V100R002
  • Application server operating system: SUSE Linux Enterprise Server 10 SP3 for X86_64
  • HBA: Emulex LPe12002

The storage device and the application server were on an DAS network as shown in Figure1.
    Figure 1 DAS network

 

When the application server and the storage device were on a DAS network and the port mode was set to Point to Point, the following symptoms may occur: The FC host port Running indicator was off and the FC host port Running Status was Offline on the ISM.

On the ISM menu bar, choose Event > Event Management. In the Event Management dialog box the fault information indicates an FC host port link-down.

Alarm Information
None
Handling Process
Set the FC host port Mode to Public Loop.
 1. Log in to the ISM and expand the storage node, and then choose Device Info > Ports in the navigation tree.
 2. Select the FC host port and right-click it.
 3. Choose Modify in the shortcut menu.
 4. In the Modify FC Port dialog box, set Mode to Public Loop.
Root Cause

Figure2 shows the chip supplier PMC's analysis.
    Figure 2 Chip supplier PMC's analysis

 

From the analysis we can see that the Emulex12002 HBA does not strictly comply with the FC protocol. It is not possible for the chip to be redesigned so this problem cannot be avoided on storage devices. Therefore, when the mode of an FC host port is set to Point to Point, due to the incompliance of the Emulex12002 HBA with the FC protocol, the application server may fail to set up a connection to the storage device.

Suggestions
When an application server is connected to a storage device by using an Emulex12002 HBA, set the Emulex12002 HBA mode to Loop or P2P (Loop preferred), and FC host port Mode to Public Loop.

END