Category: fusion

Add vCPU in VMware Fusion for Windows

Add vCPU in VMware Fusion for Windows

As Windows Pro only supports 2 CPU sockets, after added 4 cores in VMware Fusion, the OS is still shown as 2 vCPU. To avoid this is, need to change cpuid.coresPerSocket to handle more than 2 cores.


In .vmx file change following parameter, numvcpus is the total number of cores, which can be changed in GUI. cpuid.coresPerSocket should be changed to half of numvcpus.

numvcpus = "4"
cpuid.coresPerSocket = "2"


Odd behavior with Fusion 12.2 and Windows 11

Manage VMware Fusion via `vmrun`

Manage VMware Fusion via vmrun

Start VMware Fusion

$ open -a "VMware Fusion"

List running VM

vmrun list

Start a VM

vmrun start <vm_name>.vmx


Hanging at VM starting up

This could be caused by some warning message appears on the screen.


Examples of vmrun Commands
How to Open Applications Using Terminal on Mac

Unable to boot from USB in VMware Fusion

Unable to boot from USB in VMware Fusion

Fusion reports error, and it can not connect to USB drive to boot.

Fusion does not support USB adapters for connecting displays to your virtual machines.

Note: I haven't tried to change UEFI mode to BIOS mode, maybe this is the cause.


Unable to connect a USB device to a virtual machine (2118442)
USB Device not detected by the virtual machine (57195)
Configuring the USB Controller and Connecting USB Devices

VMware Fusion error – No 3D Support

VMware Fusion error - No 3D Support

Got following error when starting VM

No 3D Support is available from the Host - The 3D features of the virtual machine will be disabled


Add following lines in .vmx file

mks.enableMTLRenderer = "0"
mks.enableGLRenderer = "1"


Enabling legacy OpenGL support in Fusion 11

Permission error when run Fusion VM

Permission error when start Fusion VM


When trying to start a newly created virtual machine in VMware Fusion, following error occurred

Error: Could not open /dev/vmmon...

This is because Fusion has no permssion to open device file required.


  • Navigate to System Preferences > Security & Privacy on the host macOS (High Sierra, Mojave and Catalina).
  • Under the General tab towards the bottom of the window, you see error similar to following message with option to click on “Allow”:
System software from vendor "VMware, Inc." was blocked from loading.
  • Click Allow.
  • Restart Fusion, and start virtual machine again.
  • If some other permission errors occurr again, repeat above steps.


Error: Could not open /dev/vmmon: Broken pipe, while launching the Virtual Machine (80467)

Fusion Pools Basic

Fusion Pools Basic

Fusion Pools are also known as ZFS Allocation Classes, ZFS Special vdevs, and Metadata vdevs.


A special vdev can store meta data such as file locations and allocation tables. The allocations in the special class are dedicated to specific block types. By default, this includes all metadata, the indirect blocks of user data, and any deduplication tables. The class can also be provisioned to accept small file blocks. This is a great use case for high performance but smaller sized solid-state storage. Using a special vdev drastically speeds up random I/O and cuts the average spinning-disk I/Os needed to find and access a file by up to half.

Creating a Fusion Pool

Go to Storage > Pools, click ADD, and select Create new pool.

A pool must always have one normal (non-dedup/special) vdev before other devices can be assigned to the special class. Configure the Data VDevs, then click ADD VDEV and select Metadata.

Add SSDs to the new Metadata VDev and select the same layout as the Data VDevs.

Using a Mirror layout is possible, but it is strongly recommended to keep the layout identical to the other vdevs. If the special vdev fails and there is no redundancy, the pool becomes corrupted and prevents access to stored data.

When more than one metadata vdev is created, then allocations are load-balanced between all these devices. If the special class becomes full, then allocations spill back into the normal class.

After the fusion pool is created, the Status shows a Special section with the metadata SSDs.

Auto TRIM allows TrueNAS to periodically check the pool disks for storage blocks that can be reclaimed. This can have a performance impact on the pool, so the option is disabled by default. For more details about TRIM in ZFS, see the autotrim property description in zpool.8.


Fusion Pools