Red Hat Virtualization no longer supports software FCoE starting with version 4.4

Environment

• Red Hat Virtualiztion (RHV) 4.4 and newer with software Fibrechannel over Ethernet (FCoE)

Issue

• Starting with Red Hat Virtualization (RHV) 4.4, storage domains based on software Fibrechannel over Ethernet (FCoE) that depend on the fcoe.ko kernel module are no longer supported and will not work.
• Support for hybrid FCoE storage domains using BCM578XX cards and fcoe-utils, and full offload FCoE solutions such as qedf drivers remains unchanged

Resolution

• Customers with software FCoE storage domains that depend on the fcoe.ko kernel module should continue using RHV 4.3 until they can move to different storage. Suggested block storage alternatives include hardware based FCoE and iSCSI.
• RHV 4.3 will remain fully supported for a few months after the RHV 4.4 General Availability date. See the Red Hat Virtualization Life Cycle page for the latest support date details.
• For details on setting up FCoE with RHV, see Apendix B.3 of the Red Hat Virtualization Administration Guide.

Root Cause

• Red Hat Enterprise Linux (RHEL) 7.4 deprecated the software FCoE kernel module, fcoe.ko. It remained available and fully supported through the RHEL 7 lifecycle. See the RHEL 7.4 Release Notes.

• RHEL 8 removed the fcoe.ko kernel module.

• RHEL 8 continues to include the following native FCoE drivers:

  • bnx2fc
  • fnic
  • qedf
  • lpfc

• Since RHV hypervisors use RHEL as a base, and these drivers ship with RHEL 8, they are also supported with RHV 4.4 in the same manner as they were for RHV 4.3.

• For more on RHEL 8 FCoE, see Managing Storage Devices.

• Also see, Cannot find the FCoE kernel module in RHEL 8.

• And Fibre Channel over Ethernet (FCoE) Configuration Overview on Red Hat Enterprise Linux.

Diagnostic Steps

On a RHV 4.3 or earlier hypervisor, issue the command, lsmod | grep fcoe as root:

The output should look similar to this:

[root@example ~]# lsmod | grep fcoe
fcoe                   27527  0 
libfcoe                58854  2 fcoe,bnx2fc
libfc                 116357  3 fcoe,libfcoe,bnx2fc
scsi_transport_fc      64007  3 fcoe,libfc,bnx2fc
[root@rhva2017 ~]# 

Notice the first line:

fcoe                   27527  0

This says the usage count for the fcoe kernel module is 0 - nothing is using it - and so this RHV installation does not use software FCoE. Software FCoE was not widely adopted, and so it will be unusual for this line of output to look differently.

If your RHV environment uses FCoE, issue the command, fcoeadm -i as root from a RHV hypervisor to show the specific FCoE driver.

Look for a line starting with Driver:to find the FCoE driver. Here is an example of fully supported hardware-assisted FCoE:

[root@example ~]# fcoeadm -i eno2
    ...(output omitted)...

    Driver:           qede 8.37.0.20
    Number of Ports:  1

    ... (output omitted)...

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