For a well functioning VDI environment all components should be well tuned and optimized. For VMware Horizon View environment there are several components where optimization practices could be applied – View Connection Brokers (Connection Servers, Security Servers), vSphere infrastructure, Virtual Desktop templates or golden images, end user devices. In this article I will go through the optimizations which you can apply on your virtual machine hardware.
Virtual Machine Version
Select always the latest and greatest VM version for your template or golden image. Every new VM version add some additional features to your virtual machine. Here is the list of the native support VM version for the last four vSphere versions:
vSphere 5.0 – VM Version 8
vSphere 5.1 – VM Version 9
vSphere 5.5 – VM Version 10
vSphere 6 – VM Version 11
If you have a mixed environment and you use a single template then you must choose the lowest one, because the newest VM version is not supported on an older environment.
vCPU and vRAM
Do NOT over-provision your Virtual Desktops. For server virtualization it might not be so critical (although it is also very important), but for Virtual Desktops it is essential. Usually on a single physical server (ESXi) you run 64 to 128 or even more Virtual Desktops. Keep the pCPU to vCPU ration from 1:4 to 1:6. In a very well planned environment and specific cases you may go higher, but general recommendation is up to 1:6. Assigning too much memory to the desktops will also increase the storage requirements because of the vSWAP files, but adding less memory will hit the virtual machine performance and user experience. General recommendation is always to start with 1 vCPU and memory according the software requirements, and add more if necessary.
Network Adapter Type
VMXNET3 must be always the first choose, if you don’t have any good reason not to do it. Paravirtual driver from next generation with lot of features and low hypervisor overhead. If you provision your template from an MDT or similar tool, your boot CD might not have the vmxnet3 driver included. In that case you can choose E1000 for the provisioning phase and later switch to vmxnet3. In that case you will have to clean up the windows registries. Location where to look for it:
HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\NetworkCards
Remove all unnecessary virtual devices
I am sure you do not need a virtual floppy, don’t you? In case you see any other devices and you do not have a good justificaiton to keep them, remove all but Memory, CPU, Video Card, VMCI, SCSI controller, Hard Disk, Network Adapter. You can keep CD-ROM until you install VMware tools and then you can remove it, too. If you use Linked Clone desktops you can add it back when you need to update VMware tools only. If you use full clone desktops you most probably have 3rd party software distribution software which can be used for future VMware tools updates.
Disable Hot Plug
I’m sure you do not want your users to have the ability to unplug their network adapter by wrong click. This could be easily mitigated by adding an advanced option in the VM settings of your template.
Navigate to VM Properties -> Options -> General -> Configuration Parameters and Add devices.hotplug = False
Virtual Machine BIOS settings
Virtual machines, similar to the physical ones, have BIOS. Very often this step is being skipped, but it is important for a well functioning VDI.
Disable all you do not need! You can go to the VM’s BIOS by click ESC key in the VM console just after the VM is started. If you cannot catch the right moment you can select automatically goes to the BIOS on the next power on/restart operation.
First thing to disable is Legacy Diskette A: and B: This can be done from the Main menu.
Next step is to disable Serial and Parallel Ports and the Floppy Disk controller.
Advanced -> I/O Device Configuration
The last setting which you may want to do is the Boot Order. If the next boot will from CD-ROM, better select it as first boot device now and later switch to Hard Drive. In case you decide to follow all our recommendations you will remove CD-ROM at the end, so you do not need to come back and change the boot order.
If you have any other suggestion for VM Hardware optimization, please leave a comment.
Nikolay Nikolov
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