12.8. Using an NPIV Virtual Adapter (vHBA) with SCSI Devices

Procedure 12.6. Creating a vHBA

1. Locate HBAs on the host system

   To locate the HBAs on your host system, examine the SCSI devices on the host system to locate a scsi_host with vport capability.
   Run the following command to retrieve a scsi_host list:

   # virsh nodedev-list --cap scsi_host
   scsi_host0
   scsi_host1
   scsi_host2
   scsi_host3
   scsi_host4
   

   For each scsi_host, run the following command to examine the device XML for the line <capability type='vport_ops'>, which indicates a scsi_host with vport capability.

   # virsh nodedev-dumpxml scsi_hostN

2. Check the HBA's details

   Use the virsh nodedev-dumpxml HBA_device command to see the HBA's details.
   The XML output from the virsh nodedev-dumpxml command will list the fields <name>, <wwnn>, and <wwpn>, which are used to create a vHBA. The <max_vports> value shows the maximum number of supported vHBAs.

    # virsh nodedev-dumpxml scsi_host3
   <device>
     <name>scsi_host3</name>
     <path>/sys/devices/pci0000:00/0000:00:04.0/0000:10:00.0/host3</path>
     <parent>pci_0000_10_00_0</parent>
     <capability type='scsi_host'>
       <host>3</host>
       <capability type='fc_host'>
         <wwnn>20000000c9848140</wwnn>
         <wwpn>10000000c9848140</wwpn>
         <fabric_wwn>2002000573de9a81</fabric_wwn>
       </capability>
       <capability type='vport_ops'>
         <max_vports>127</max_vports>
         <vports>0</vports>
       </capability>
     </capability>
   </device>   

   In this example, the <max_vports> value shows there are a total 127 virtual ports available for use in the HBA configuration. The <vports> value shows the number of virtual ports currently being used. These values update after creating a vHBA.

3. Create a vHBA host device

   Create an XML file similar to the following (in this example, named vhba_host3.xml) for the vHBA host.

   # cat vhba_host3.xml
      <device>
        <parent>scsi_host3</parent>
        <capability type='scsi_host'>
          <capability type='fc_host'>
          </capability>
        </capability>
      </device>   

   The <parent> field specifies the HBA device to associate with this vHBA device. The details in the <device> tag are used in the next step to create a new vHBA device for the host. See http://libvirt.org/formatnode.html for more information on the nodedev XML format.

4. Create a new vHBA on the vHBA host device

   To create a vHBA on vhba_host3, use the virsh nodedev-create command:

   # virsh nodedev-create vhba_host3.xml
   Node device scsi_host5 created from vhba_host3.xml

5. Verify the vHBA

   Verify the new vHBA's details (scsi_host5) with the virsh nodedev-dumpxml command:

   # virsh nodedev-dumpxml scsi_host5
   <device>
     <name>scsi_host5</name>
     <path>/sys/devices/pci0000:00/0000:00:04.0/0000:10:00.0/host3/vport-3:0-0/host5</path>
     <parent>scsi_host3</parent>
     <capability type='scsi_host'>
       <host>5</host>
       <capability type='fc_host'>
         <wwnn>5001a4a93526d0a1</wwnn>
         <wwpn>5001a4ace3ee047d</wwpn>
         <fabric_wwn>2002000573de9a81</fabric_wwn>
       </capability>
     </capability>
   </device>