VM

How do I resolve the failure to start a VM (vm01 for example) in an HA cluster?

Condition

This issue might occur when the following conditions exist:

Solution

To resolve this issue:

  1. Verify that the VM disk file exists with a non-zero file size:

  1. In the navigation tree in CVM, expand Cloud Resources, and then navigate to vm01.

  1. In the Summary tab, identify the path of the VM disk file. In this example, the file path is /vms/target3/vm01.

  1. In the navigation tree, navigate to the host that contains vm01. Then, select the target at /vms/target3 in the Storage tab to verify that a VM disk file exists for vm01 and the file size is not zero.

  1. If a CD/DVD drive has been mounted on the VM, make sure the drive exists, whether it is a physical CD/DVD drive (/dev/cdrom) or an .iso virtual drive file (,/vms/isos/winxpsp3.iso for example), as follows:

  1. From the navigation tree, select the VM under Cloud Resources.

  1. Click Edit VM.

  1. In the navigation pane on the VM modification page, select CD-ROM, and verify the CD/DVD drive setting:

  1. Verify that the vSwitches connected to the NICs of the VM exist and the profiles applied to the NICs exist and are correct.

  1. Verify that the VM disk file type is correct:

  1. Identify the disk file type (qcow2 for example) as described in step 1.

  1. Open the VM modification page, select the Disk option in the navigation pane, and check the Storage Format field in the right pane. Typically, the storage format is intelligent for a qcow2 file and high-speed for a raw disk file.

  1. Verify that the host has sufficient memory for the VM. If memory runs low, add physical memory or free up memory by temporarily shutting down the idle VMs that are running.

What should I do if a Windows VM enabled with memory limit cannot be started?

Symptom

A Windows VM enabled with memory limit cannot be started.

Condition

This symptom might occur if the memory size configured for a Windows VM is larger than the memory size specified in the memory limit feature. After you enable memory limit for a VM, the limited memory will be switched to the Swap partition. If the Swap partition does not have sufficient space, the VM cannot be started.

Solution

Before enabling memory limit, make sure the Swap partition has sufficient space.

What should I do if I cannot reinstall a Windows guest OS for a VM after an unexpected host shutdown event caused an installation failure?

Symptom

I cannot reinstall a Windows guest OS for a VM after an unexpected host shutdown event caused an installation failure.

Solution

To resolve this issue, use either of the following methods:

What should I do if the VM console does not respond to the keyboard input?

Symptom

The VM console does not respond to the keyboard input after a failed attempt at pressing Ctl+Alt+Del to restart a Windows VM that has failed to start up.

Condition

This issue typically occurs if the VM disk is corrupt or no guest OS is installed.

Solution

To resolve this issue:

Why does the system display a failure message for a successful VM operation (start or shutdown for example) on a cluster?

Symptom

The system displays a failure message if you perform a VM operation (start, restart, shutdown, or put-to-sleep for example) on an HA cluster or on a cluster on which HA is being enabled or disabled.

Condition

This issue is most likely to occur in the following situations:

Solution

To resolve this issue:

  1. Avoid performing VM operations on an HA cluster member host while the host or the network is busy.

  1. Make sure the VM has a correct storage and network configuration before you start it.

Failed to shut down or restart VMs on CAS

Symptom

I receive the " Disabling IRQ #10 BUG:Soft lockup -CPU#0 stuck for 67s! [migration/0:5]" error message when I attempt to shut down or restart some VMs that use a Linux guest OS.

Condition

This issue typically occurs if a VM uses a virtio NIC, which has poor compatibility with some versions of Linux.

Solution

When this error message occurs, the VM shutdown procedure is almost finished. You can power off the VM from CAS to force the VM down without incurring problems.

What should I do if I receive a cluster process not started error message when I attempt to start, shut down, or move a VM in an HA cluster?

Symptom

A cluster process not started error message is displayed when a VM is started, shut down, or moved in an HA cluster.

Condition

This issue occurs if HA service is not started on the host that contains that VM.

Solution

To resolve this issue, start HA service on the host by using one of the following methods:

What should I do if an error occurs when I add storage volumes or clone a VM?

Symptom

The "internal error pool iSCSITarget8-lun1 has asynchronous jobs running" error message is displayed when storage volumes are added or a VM is cloned.

Condition

This issue occurs if you perform an operation that requires concurrent accesses to multiple volumes in a storage pool, including:

Solution

To avoid this issue, create volumes or clone VMs one by one if they are in the same storage pool.

What should I do if the system displays that the destination storage volume file already exists during a VM operation?

Symptom

The system displays that the destination storage volume file already exists during a VM operation (migration, clone, deployment, or template creation through clone or conversion).

Condition

This issue occurs when the system detects that the target storage pool contains a volume file that has the same name as the source file.

Solution

To resolve this issue, delete the volume file contained in the target storage pool if that file will not be used any longer, and then perform the VM operation again. If that file will still be used, perform the VM operation again and does the following during the procedure:

How do I resolve the failure of a VM to find its disk at startup after a VM operation is performed between CVMs?

Symptom

A VM failed to find its disk at startup after a template-based VM deployment, VM backup, VM import, or import of P2V or V2V files is performed between CVMs.

Condition

This issue typically occurs if a VM (an openSUSE-based VM for example) depends on the CID file of CVM to identify disk partitions. Different CVMs have different CID files. The VM will fail to find its disk when it is managed between different CVMs.

Solution

To resolve this issue, change the disk partition identification method from by-id to by-uuid or by-path in the /etc/fstab file.

What should I do if CVM displays that the storage file already exists when I attempt to import a VM that has failed to be imported from a local directory because of an unknown error?

Symptom

CVM displays that the storage file already exists when I attempt to import a VM that has failed to be imported from a local directory because of an unknown error.

Condition

This issue typically occurs if the network connection to a host is lost while CVM is importing VMs from a local directory to that host but the script is still being executed in the back end. After the VMs are imported successfully in the back end, the front end does not receive a message and reports an unknown exception. The front end calls the script but does not obtain the success result, so it will not save the VM data to the database or refresh the storage pool.

Solution

To resolve this issue:

  1. Connect to the host.

  1. Delete the VMs that failed to be imported to the host.

  1. Refresh the storage pool that contains the image files of those VMs, and then delete the VM image files.

  1. Import the VMs again after the network gets stable.

VM operation failure, unexpected VM suspension, or unexpected VM status change to unknown occurred

Symptom

VM operation failure, unexpected VM suspension, or unexpected VM status change to unknown occurred.

Condition

This issue typically occurs if the root directory of the file system on the host runs out of disk space.

Solution

To resolve these VM issues, delete or move unused files from the root directory on the host until sufficient free space is available. As a best practice, make sure the root directory has a minimum of 2G space.

How do I deal with the failure to connect to the host during a VM operation?

This issue occurs if the number of Libvirt connections to the host exceeds the limit. To resolve this issue, wait a while and then try again.

Online VM migration failed after HugePages memory is enabled for the VM

Symptom

Online VM migration failed and an error message is displayed after the HugePages memory is enabled for the VM.

Solution

To resolve this issue, shut down the VM and set its memory size to an integer multiple of the memory page size of the destination host. To add memory resources to the VM online after the VM is enabled with HugePages memory, make sure the size of the added memory resources is also an integer multiple of the memory page size of the destination host.

How do I resolve the network communication error or the jumping to the CVM login page issue that occurs when I bulk-operate VMs on a host?

Symptom

A network communication error occurs or the system jumps to the CVM login page when VMs are bulk-operated on a host.

Condition

This issue might result from frequent console refresh operations.

Solution

To avoid automatic jumping to the CVM login page, reduce the number of VMs in each bulk operation after you re-log in to the CVM.

To avoid communication errors, refresh the page, re-log in to CVM, and reduce the number of VMs in each bulk operation.

Why does a VM enter unknown state after a DRX task is executed in a stateful failover system, and what should I do?

Symptom

A VM enters unknown state after a DRX task is executed in a stateful failover system.

Condition

The VM enters unknown state because the following conditions exist:

Solution

To resolve this issue:

  1. On the top navigation bar, click Resources.

  1. From the left navigation pane, select Host Pool Name > Cluster Name > Host Name or Host Pool Name > Host Name to enter the configuration page of the host to which the VM belongs.

  1. Click More, and then select Connect Host.

  1. Click OK.

  1. The VM will be deleted from both the host and the DRX service after the host is reconnected to CVM.

How do I resolve the failure to set up the network by using CAStools?

Symptom

I cannot set up the network by using CAStools after a VM is deployed based on a Red Hat Enterprise Linux 7 template.

Condition

This issue occurs because the VM cannot establish a session with the NetworkManager daemon, which is by default used in Red Hat Enterprise Linux 7 to monitor and manage the network setup. When you use CAStools to change the IP address of the VM, the CAStools cannot establish a session between the VM and NetworkManager. Network setup will fail after the VM restarts.

Solution

To resolve this issue, install the most recent version of CAStools on the VM, use the chkconfig NetworkManager off command to disable NetworkManager, and then reconfigure the template.

Why doesn't a serial port shared by multiple VMs respond to the instructions from any of the VMs?

Condition

This issue occurs because the serial port cannot identify which VM is communicating.

Solution

To resolve this issue, make sure only one of the VMs is running.