Frequently Asked Questions

From where do I download Cumulus VX images?

Cumulus VX is available as a free download on the Cumulus Networks website. You must create an account and log in to download a Cumulus VX image. Images are available for all supported hypervisors.

Which Hypervisors does Cumulus VX support?

For a list of the supported hypervisors and orchestrators, see supported hypervisors.

What is the support policy for Cumulus VX?

The support policy for Cumulus VX depends on whether you are a customer or non-customer. See Support Policy.

What is the difference between Cumulus VX and Cumulus Linux?

The intent of Cumulus VX is for simulation, testing, and training. Cumulus Linux is the software running directly on NVIDIA switches. Cumulus VX is not a production-ready virtual switch or router. See Cumulus VX Compared with Cumulus Linux.

I have platform and disk limitations for Cumulus VX, how do I try Cumulus Linux?

Try Cumulus in the Cloud, which is a free, personal, virtual data center network that provides a low-effort way to see NVIDIA Networking technology in action. This is a good way to try out Cumulus Linux if you have platform or disk limitations.

How do I log into the Cumulus VX switches?

  • For Cumulus VX 4.1.1 and earlier, log into each switch with the cumulus account and default password CumulusLinux!. You are not prompted to change the default password.
  • For Cumulus VX 4.2 and later, log into each switch with the cumulus account and default password cumulus. When you log in for the first time, the OS prompts you to change the default password.

For more information on the required password change, see the Cumulus Linux documentation.

Why do I see the failure: Unable to find storage device for file system with label ONIE-BOOT?

In VMware vSphere, you might see this failure if you select the wrong storage interface type (SATA or IDE). For example this log message indicates vSphere cannot find the filesystem.

Info: Fetching http://192.168.100.1/onie-installer-cumulus_vx ...
ONIE: Executing installer: http://192.168.100.1/onie-installer-cumulus_vx
Verifying image checksum ...OK.
Preparing image archive ... OK.
Verifying image compatibility ...OK.
Verifying system ram ...OK.
Setting up installer ...Failure: Unable to find storage device for file system with label 'ONIE-BOOT'
Info: Check the output of 'blkid'.

Configure VMware vSphere to use the SATA controller.

Why do I see the error br0: received package on swp1 with own address as source address?

If you intend to bridge the switch ports in the VM, place each switch port in the bridge in its own virtual network on the host. Otherwise, you might see this error:

br0: received package on swp1 with own address as source address

How do I redirect the GRUB menu and the kernel output to the serial console?

To provide easier access in video-focused hypervisors (such as VirtualBox), the default Cumulus VX configuration redirects the GRUB menu and the kernel output to the video console.

Follow these steps to send both the GRUB menu and the kernel output back to the serial console.

  1. Interrupt the boot process at the GRUB prompt.
  2. Modify the Linux command line directly, removing all references to the console entries.
  3. Start the VM.
  1. Run the following commands as the sudo user:

    cumulus@switch:~$ sudo sed -i 's/^#//' /etc/default/grub.d/00-installer-defaults.cfg
    cumulus@switch:~$ sudo sed -r -i '/^GRUB_CMDLINE_LINUX=/ s/(console=ttyS0,115200n8) (console=tty0)/\2 \1/' /etc/default/grub
    cumulus@switch:~$ sudo update-grub
    
  2. Restart the VM.

Why do I see a the error: net could not connect to netd when I try to run NCLU commands?

Based on the underlying CPU resources, it might take some time for the NCLU service to start after you boot the switch. If you issue an NCLU command before the NCLU service starts, you see the message:

ERROR: net could not connect to netd

Either wait a bit longer for the NCLU service to start or run the command sudo sytemctl start netd.

If you start Cumulus VX with less than the required 768MB of RAM, the NCLU service might fail to start.

When using VirtualBox or VirtualBox with Vagrant, why is the bond I create down?

With VirtualBox or VirtualBox with Vagrant, when you create a bond, make sure to set promiscuous mode to on for each interface:

  1. For VirtualBox, make sure to set all adapters (except Adapter 1) to Promiscuous Mode: Allow All under network settings in the VirtualBox Manager. See VirtualBox.

    For VirtualBox and Vagrant, make sure the Vagrantfile contains the promiscuous mode setting for all interfaces. See the example Vagrantfile in VirtualBox and Vagrant.

  2. On each switch, set promiscuous mode for all interfaces in the /etc/network/interface file. For example:

    auto swp2
    iface swp2
        #required for traffic to flow on Bonds in Vbox VMs
        post-up ip link set $IFACE promisc on
    
    auto swp3
    iface swp3
        #required for traffic to flow on Bonds in Vbox VMs
        post-up ip link set $IFACE promisc on
    

Cumulus VX does not boot on Nutanix AHV

When using Nutanix AHV as a hypervisor, during the boot process of Cumulus VX, you see the following error:

 Gave up waiting for root file system device. Common problems:
  - Boot args (cat /proc/cmdline)b302-e5056ce95126
     - Check rootdelay= (did the system wait long enough?)
  - Missing modules (cat /proc/modules; ls /dev)
ALERT! UUID=92d167d9-116d-4290-8552-5ce3c50bd4a8 does not exist. Dropping to a shell!

BusyBox v1.30.1 (Debian 1:1.30.1-4) built-in shell (ash)
Enter 'help' for a list of built-in commands.

(initramfs)

Using the AHV default SCSI disk type instead of SATA causes this issue. Change the disk type under the VM details to SATA and restart the Cumulus VX VM.