FAQ

After VMs on a host are migrated to a destination host because of host failure, I shut down the VMs and the destination host. Why does the state of the failed host frequently switch between normal and maintenance after it recovers?

This is a normal phenomenon for High Availability (HA). After the failed host recovers, it will synchronize VM information. However, the destination host has been shut down and the recovered host cannot confirm with the destination host whether the related VMs exist. As a result, the recovered host cannot complete VM synchronization, which causes frequent normal/maintenance state switches. In this case, start the destination host for the recovered host to complete VM synchronization.

Do I need to install a client for accessing CVM?

No.

To access CVM, enter http://CVM management IP address or https://CVM management IP address in the address bar of the Web browser. The following are CVM address examples:

Why do some CVM pages look different when they are accessed from different browsers?

This is because the browsers interpret some page elements differently. This issue is normal and does not affect the functionality of the product.

Why does the system prompt error 502 when I access CVM?

The system will restart Tomcat during secure mode switching, stateful failover system setup, or patch upgrade and this will cause temporary access interruption. You can access CVM correctly after a while.

What are the VM image file requirements for a VM migration?

To move a VM between hosts without moving its storage, make sure the following requirements are met:

To move a VM with its storage between hosts or move only the storage of a VM, make sure the following requirements are met:

Are there any file system access requirements for VM backup?

Yes. The requirements vary depending on the backup method, as follows:

What should I do when some incremental VM backup files are lost?

If an incremental backup file before a point in time is deleted or lost, you will be unable to restore the VM to that time point. To ensure a successful future VM restoration, select the VM in the navigation tree. In the backup management tab for the VM, perform a full backup before you continue with the incremental method of backup.

Why can't some guest OSs display all serial ports added on VMs?

This issue occurs because of the limitation intrinsic to the guest OS.

Is it normal that CVM merges multi-level images of a VM after that VM is imported or restored?

Yes, it is normal that CVM merges multi-level images of a VM after that VM is imported or restored.

How do I handle the volumes that have a suffix of _base_0 or _base_1 in the storage pool if no users are using them?

After the file merge, CVM removes the VM from the user lists of the image files linked to the VM (image file with a suffix of _base_0 or _base_1 for example).

If the user list of an image file is empty, no VMs are using that file. You can delete that image file to free up storage space.

How do I update the Virtio disk driver after I select a Virtio disk for a VM?

The update procedure depends on the guest OS. The following is the generic update methods for Windows 7:

What requirements does CVM have for the managed hosts?

The managed x86 hosts must use CPUs that support Intel-VT or AMD-V for virtualization.

The managed ARM hosts must use ARM8.1 or higher CPUs and support VHE.

Recommended hardware settings:

What should I do if a VM does not support specific instruction sets (such as AVX, AVX2, AUX)?

Identify whether the physical CPU supports those instruction sets. If they are supported, perform the following task:

  1. Set the CPU operating mode to passthrough or EMC for the VM.

  2. Shut down the VM, and then restart it.

    If you restart the VM without shutting it down, the new CPU operating mode will not take effect.

Can I use the asterisk (*) and question mark (?) as wildcards when I search for information in CVM?

Yes. The asterisk (*) matches a character string of any length, and the question mark (?) matches any single character. You can use them as wildcards in any searches except when you use the search field in the top right corner or search the storage volume list of a storage pool.