In the FusionSphere architecture, which of the following options are optional components? (Multiple choice)

The virtual machine in the KVM virtualization platform consists of at least two files. One is the virtual machine configuration file, and the other is the virtual machine speed disk file.

Three virtual machines share a CPU thread, the main amount is 2.86GHz, the resource of VM1 is reserved for 1000MHz, and VM2 and VM3 do not reserve resources.
The quota of VM1 is 1000, the quota of VM2 is 2000, the quota of VM3 is 4000, and 2000MHz is displayed on the three virtual machines. When the CPU usage rate of the three virtual machines is 100%, the CPU resource bit of VM3:

Which of the following statements about disk performance is correct?

Which scenario is recommended to use disk raw device mapping