Create a VOI image source VM
The system supports creating VOI image source VMs with the default C106V, C106V Plus, C107V, C107V Plus, C107V Pro, C108V Plus, C108V Pro, C200V, C201V, C206V, C206V Plus, C207V, C207V Plus, C207V Pro, C208V Plus, and C208V Pro configurations to adapt to VOI endpoints with the corresponding models. The system also allows you to select the VOI endpoint configuration customized in Flavor configuration to adapt to non-default VOI endpoints.
Restrictions and guidelines
ARM hosts do not support VOI desktop images in current software version.
The C200V endpoints support only Windows 10 version 1709.
Procedure
From the navigation pane, select Images > Desktop Images.
Click the Image Source VMs tab. Click Create.
On the page that opens, select image type VOI, configure the image source VM parameters, and click OK.
Parameters
Host: Select the host where the image source VM resides.
Image Type: Specify the desktop architecture type that the image applies to. Available options include VDI, IDV, and VOI.
Type: Specify a disk type for the image source VM. Available options include File, Create RBD, and Block. Options for the File type include New File or Existing File. When an active RBD storage pool exists on the host, the default is Create RBD. In the other cases, the default is New File.
New File: For the VM, a file is a disk based on a virtual disk file. This disk type is more manageable than the block device disk type. If you select this option, an empty storage file is created as the disk of the VM.
Create RBD: If you select this option, create an RBD as the disk of the VM in an RBD storage pool.
Existing File: Specify an existing storage volume that is not used by other VMs. You can select a volume from the local file directory, shared file system, or network file system storage pool as the disk of the VM.
Block: A block device is also called a raw device that does not have a file system, for example, a storage LUN on an IP SAN or FC SAN. Block devices are typically used in a virtualization environment that requires high performance, for example, databases and high-performance I/O compute. Select this option to an existing storage volume that is not used by other VMs as the disk for the VM. You can select a volume from the RBD, iSCSI, FC, or LVM logic storage pool as the disk of the VM.
Path: The path acts as the storage path for image source VM file rather than the final desktop image. The /vms/images and /vms/isos paths are local paths. As a best practice, select another path in case that the local directory space is insufficient. When creating a VOI image source VM, make sure the available space of the storage path is greater than the endpoint system disk size specified in the selected flavor.
Flavor Configuration: Configuration of the VOI endpoints that the image source VM applies to. You can select the system-default VOI endpoint flavor or a self-defined VOI endpoint flavor defined in Flavor configuration. Make sure the model of the selected flavor is the same as that of user endpoints. For example, if the user endpoint model is C206V, select the flavor named C206V. The system disk size in the selected flavor is the recommended value for best experience. As a best practice, do not modify it. For how to modify the flavor, calculate the VOI endpoint disk space as follows: Total disk space = Space used by the endpoint OS (about 4 GB) + data disk space + space used by the VHD image file + system disk space + free space. The system disk space and data disk space are configurable, and the free space can be flexibly used. When a VOI endpoint runs a client OS, the endpoint will load the VHD image file in the disk into the system disk and run it. In this case, the system disk space = space used by the client VHD image file + free system disk space. The following figure uses a C206V endpoint as an example. In this example, the default data disk space is 2 GB, the default system disk space is 120 GB, and the VHD image file size is 15 GB. In this case, the disk space usage of the VOI endpoint is as follows.
You must follow these steps to calculate and plan the system disk space and data disk space in the VOI flavor.
According to the application scenario of the Winswap data disk, set the data disk space, as shown in the figure above.
Estimate the VHD image file size, including the size of the pure operating system and the size of the applications to be installed.
In the education scenario, to switch between multiple images, you must plan the space of other VHD image files and reserve the space in the free space.
After the plan above, calculate the system disk space.
Operating Mode: Set the CPU operating mode. Options include Compatible, Host Matching, and Passthrough. By default, the CPU operating mode is Compatible.
Compatible: Virtualizes physical CPUs of different models into vCPUs of the same model. This mode feature high migration compatibility.
Host Matching: Virtualizes physical CPUs of different models into vCPUs of different models. This mode features low migration compatibility but provides better performance for VM operating systems than the Compatible mode.
Passthrough: Directly passes physical CPUs to VMs. This mode features low migration compatibility but provides better performance for VM operating systems than the Compatible mode and Host Matching mode. VMs using the passthrough CPU operating mode can be migrated only between hosts with the same CPU model. ARM hosts support only the passthrough mode.
Network: Select the vSwitch for the image source VM network communication.
System Image: Pure ISO image for the operating system used by the image source VM.
File Name: Enter the file name of the disk if a new file is used as the disk. Select a disk formatting mode, VOI image source VM only support Intelligent (qcow2).
Provision: Select a storage volume provision mode. Options include Thin (the default), Lazy Zeroed, and Eager Zeroed. This field is required when the disk type is New File.
Thin: Allocates only as much storage space as the storage volume needs for its initial operations when the storage volume is created. If the storage volume needs more storage space later, the system allocates as much storage space as the volume would require based on the specified maximum storage size.
Lazy Zeroed: Allocates the specified maximum storage size to the storage volume when the storage volume is created. Data remaining on the physical device is not erased during creation, but is zeroed out on first write from the VM.
Eager Zeroed: Allocates the specified maximum storage size to the storage volume when the storage volume is created. Data remaining on the physical device is zeroed out during creation. It might take a longer time to create storage volumes in this format than to create storage volumes of other formats.
Disk Cluster Size: Set the smallest amount of disk space that can be used to store a file. The default is 256 KB. If a file is larger than a disk cluster, it is stored in multiple disk clusters. If a file is smaller than a disk cluster, it is stored in a dedicated disk cluster. A shared file system is mainly used to store VM image files. As a best practice, set the value of this parameter as large as possible to enhance disk read performance and save disk space. You must configure this parameter when you add an intelligent disk.
Bus Type: Select a bus type. Options include IDE, USB, High-Speed (the default), and High-Speed SCSI.
Cache Mode: Select a cache mode for VM storage files. Options include Directsync, Writethrough, Writeback, and None. The default cache mode for intelligent disk format is Directsync. For raw or block (including RBD) device disk format, the default cache mode is None.
Directsync: The system reads data from the physical disk.
Writethrough: The system writes data to the host cache, and then to the physical disk.
Writeback: The system writes data to the VM cache, then to the host cache, and finally to the physical disk.