Network Issues

MAC Address Displayed on the Engine for the Non-Primary Subordinate Port of a Bond Not Synchronized With KVM Host

After a bond is created on an KVM host with 2 subordinate ports, the MAC address of the non-primary subordinate port is changed to be the same as the primary subordinate port on the KVM host, but the Manager continues to display the previous MAC address of the subordinate port.

Solution: There is no workaround for this behavior.

Bug: 29049447

Engine Does Not Update the IP Address of a Virtual Machine When Switching the Virtual Machine Network for a Running Virtual Machine

In a scenario where a virtual machine is running with one VNIC interface connected to a VM network, it is observed that the Manager allows the user to change the VNIC interface for the running virtual machine to a different VM network. This action causes the virtual machine to lose its VM network and to become inaccessible (that is, its IP address is no longer pingable). The Manager, however, still displays its old IP address and does not generate any error messages.

Solution: There is no workaround for this behavior.

Bug: 29060999

Default Route Still Set to Yes After Default Route Role Is Removed from Connected Network

Changing the default route on a network that is attached to a host and that has virtual machines connected to that network is illegal and is rejected by VDSM. The Manager host gets notified about the request failure and logs the error, but the Manager is unaware of the failure; that is, the Manage Networks pane shows that default route change was successful.

Solution: When you modify the network configuration, make sure the interface configuration accurately reflects the most recent changes.

Bug: 29133844

Exception Generated When VLAN Network Is Added with Interface Name Longer Than 15 Characters

Adding an VLAN interface whose interface exceeded 15 characters generates the following failure message: 

VDSErrorException: Failed to HostSetupNetworksVDS, error = Internal JSON-RPC error: 
{'reason': '[Errno 8] Input data out of range'}, code = -32603

The VLAN ID ranges from 0 to 4096, which is a maximum of four characters and the total interface name has a limit of 15 characters. This is a Linux kernel limitation. The maximum interface name length is defined by the kernel headers and is a global limit, affecting all applications.

Solution: Limit interface names to 15 characters (including periods and VLAN IDs).

Bug: 29221397

Adding KVM Host Connected to VLAN Network Fails When VLAN Network Is Not Configured on Management Network

Adding a KVM host that is connected to a VLAN network fails when the ovirtmgmt management network is not configured on the VLAN network.

Solution: All servers that are part of a single cluster must be on the same VLAN management network.

Perform the following steps:

  1. Go to Network and then click Networks.
  2. Select the ovirtmgmt network under the Name column.
  3. Click Edit.

  4. Select the Enable VLAN tagging checkbox and enter the VLAN tag ID in the text entry field.

    Make sure that the VLAN tag ID is the same as the VLAN ID set on the host interface to be connected to the ovirtmgmt management network.

  5. Go to Compute and then click Hosts.
  6. Click New.
  7. On the Hosts pane, click on the KVM host.
  8. Click on the Network Interfaces tab.
  9. Click Setup Host Networks and add the ovirtmgmt management network to the appropriate interface.

Bug: 29245869

Network Synchronization Fails but Is Reported as Succeeding

After creating a VLAN network with a MTU value and adding the network to a host interface, the network is not synchronized because the host retains the default MTU value of 1500. When clicking Sync All Networks, the Manager reports the following message, indicating that the network synchronization is completed: 
Finished Synchronizing networks on host
The network, however, is still not synchronized.

Solution: Try clicking Sync All Networks again.

Bug: 29311422

KVM Host Becomes Non-Operational When a Bondport Connected to Virtual Machine Network Changed from an Unsupported Mode to a Supported Mode

When a bondport is created with a mode that is not supported for a VM network, the network can be connected to a non-VM network successfully; however, if the non-VM network is changed to VM network, the network becomes out of sync. Furthermore, if the user follows the instructions provided in the error message to fix the network issue, the KVM host becomes non-operational. This issue is caused by the network change (non-VM to VM network) combined with the bond mode change.

Note:

No issues occur when performing these actions in reverse; that is, changing a VM network to a non-VM network and then changing the bond mode accordingly.

The steps to reproduce this issue are as follows:

  1. Create a non-VM network and connect the network to a bondport mode in 0, 5, or 6.

  2. Change the network mode to a VM Network by editing the network in the Manager and selecting the VM Network checkbox.

    This action causes the network to become out of sync.

  3. Click Sync All Networks.

    The following error is generated: Network name is attached to bond number . VM networks cannot be attached to bonds in mode 0, 5 or 6.

  4. Change the bond mode to a mode available for a VM network (1, 2, or 4) and click OK.

    After the network setup window closes, the Sync All Network button appears again, indicating that the network is out of sync, and the host becomes non-operational.

Solution: You can click Sync All Networks again to bring the KVM host up. Alternatively, to bring the KVM host up, you can put this KVM host in Maintenance mode and activate it after the network is back in sync.

Bug: 29312752

Engine Does Not Check Connectivity When Removing an Interface

When you connect a host interface to a network, the Manager validates their connectivity before establishing the connection. However, when removing an interface, the Manager does not check their connectivity. This behavior is observed in a network configuration where the management network is already connected to a bondport with 3 or more subordinate ports and only 1 of the ports is in UP state and is able to communicate with the management network.

In this situation, when you attempt to remove the UP port (primary port) in the Setup Host Networks dialog box, the Manager generates the following Operation Canceled error message: 
Error while executing action HostSetupNetworks: Could not connect to peer host
This error message, which is generated during the removal of the subordinate port, is referring to the new connection that cannot be established, even though the removal of the primary port has already occurred.

Solution: There is no workaround for this behavior. In this situation, you need to make sure the remaining communication between the bondport and the management network are not interrupted after the subordinate port is removed, otherwise the host loses connection with the Manager and becomes non-responsive.

Bug: 29338703

Network Scale Limitation When Adding Networks to a KVM Host

In an Oracle Linux environment you can add approximately 389 networks to a KVM host, after which network communication timeout errors start appearing in the Manager log file and no further networks can be added to the host.

Solution: There is no workaround for this behavior.

Bug: 29383782

Network Label Failure Generates Illegal Network Parameters Error When Performing Other Network Operations on the KVM Host

In a scenario where two VLANs are erroneously created with duplicate VLAN numbers, a warning in the form of an orange exclamation mark appears as expected in the Manager next to the duplicate VLAN on the Setup Host dialog box with the following error message: 
Cannot have networks with duplicate vlan id on same interface.
After this network configuration error, attempting to perform other network operations on the KVM host generates the following Operation Canceled error message: 
Error while executing action HostSetupNetworks: Illegal Network parameters

Solution: You must resolve the network label failure before other network operations can be performed.

Bug: 29424399

Cannot Modify a VNIC in a Running Virtual Machine if an MTU Value is Set

If a virtual machine is running, editing a VNIC that has an MTU value set fails with the following message: 

 Error while executing action Edit VM Interface properties: General Exception

The following message is displayed in the /var/log/vdsm/vdsm.log file: 

 libvirtError: Operation not supported: cannot modify MTU

Solution: Shut down the virtual machine before editing the VNIC. A known issue in the upstream oVirt release.

Bug: 29456945

VM Network Bridge Name Does Not Match VM Network Name

When you create a new VM network, VDSM creates a bridge named after the VM network and its associated configuration file (/etc/sysconfig/network-scripts/ifcfg-vm_network) on the Oracle Linux KVM hosts.

If the VM network name is longer than 15 characters, or it contains special characters or a space character, VDSM generates a name for the bridge and the configuration file in the format "onXXXXXXXXXXXXX " where XXXXXXXXXXXXX is the first 13 hexadecimal characters extracted from the UUID of the network.

This is a Linux kernel limitation, bridge names must be 15 characters or less, and must not contain any special characters.

Solution: Limit VM network names to 15 characters and avoid any special characters.

Bug: 29409851