VM settings reference

VM Settings has six pages: General, Display, Storage, Network, Sharing, and Advanced — and a seventh, Cloud-Init, on Linux VMs made from a cloud image. Before saving, MacVisor summarises what your edits will cost: applied live, applied on the next restart, or applied on restart with saved memory state discarded.

General

Identity — name, icon, and up to 256 characters of notes shown on the Overview tab.

Resources — vCPU count and memory size. Both need a restart and invalidate saved state.

Startup — Start at Login asks MacVisorService to start the VM headless with each login session. A VM suspended at logout resumes from its saved state instead of cold-booting. See Always-on host.

Window — what closing the VM window does (hide, ask, or shut down) and whether the VM opens in a separate window by default.

Display

• Headless removes the graphics device entirely — the right choice for servers and automation.
• Accelerated Graphics uses Apple's Mac graphics device for macOS guests. Linux guests use software-rendered Virtio graphics; Metal acceleration is macOS-guest only.
• Match Window Size adjusts guest resolution to the window on guests that support it.
• Primary Display takes a preset (1080p, 1440p, 4K, Studio Display 5120×2880, Classic 1920×1200) or a custom resolution and PPI.
• Additional Displays are supported for macOS guests; each gets its own window in the runner.

Storage

Boot Disk — the disk's file name, capacity, and format are shown; the format is not editable, because MacVisor creates ASIF and keeps legacy raw disks as they are.

• Resize… on an ASIF disk grows or shrinks it. On a raw disk the button reads Expand… and only grows. mvz set <vm> --disk <GiB> grows from the command line; a Linux VM made from a cloud image grows its filesystem at the next boot.
• Convert to ASIF… appears for a raw disk on a stopped VM.
• Bus — Virtio or NVMe — plus caching and synchronisation policy.

See Storage and sharing for conversion requirements and the free-space rule.

Additional Disks — create, attach, resize, or remove extra ASIF images. Removing a managed disk moves its image to the Trash.

Disk Images — ISOs and raw images attached by path on a chosen bus at next start. Images on the USB bus can also be hot-attached while the VM runs, from here or the Overview tab, when Allow Runtime USB Mass-Storage Attach is on. Compressed or sparse .dmg files are not supported.

Network

Primary interface — NAT, bridged (choose the host interface), or a custom network. Additional interfaces add more NICs.

Host port forwarding — per-VM TCP or UDP forwards from a host address and port to a guest port, relayed through the guest agent over vsock. These apply immediately to a running VM once guest tools are connected. A VM made from a cloud image also forwards the ports its guest listens on automatically, to 127.0.0.1 at the same number.

See Networking and Custom networks.

Cloud-Init

Shown for Linux VMs made from a cloud image. It holds what cloud-init was given for the first boot: the hostname; the account (user name, full name, and the UID it mirrors from your Mac account); the container runtime — containerd, Docker, Podman, k3s, or none; whether to install the guest agent; the SSH authorised keys, one per line and checked as you type; and your own user data, a #cloud-config or script applied after MacVisor's. The hostname and account are what cloud-init sets up in the guest; the runtime and agent are installed from the guest-tools image on the first boot. Changing these after the VM has booted once changes what a re-provisioned guest would get, not the guest that already exists. To re-provision, turn on Set up again on next start: the next boot runs cloud-init as for a new machine, applying these keys and user data and giving the guest a new identity (it may get a new address).

Sharing

Shared Folders — expose host folders to the guest under a tag, optionally read-only. Mount inside the guest by tag.

Clipboard — whether clipboard synchronisation starts enabled.

Guest Tools — Enable Guest Tools turns on the host side of the agent channel; Attach Guest Tools Image at Boot mounts the MacVisor Agent volume at each start. The channel needs the Virtio Socket (vsock) device from Advanced. See Guest tools.

Rosetta — mounts Rosetta into Linux guests so they can run x86_64 Linux binaries.

Guest-initiated file, URL, and automatic port-forward requests always require approval regardless of these settings.

Advanced

Keyboard and Pointer — attach a Mac keyboard and Mac trackpad for macOS guests; a USB keyboard and pointing device stay attached as a compatibility fallback.

Input Capture — Capture system keys sends shortcuts such as ⌘Tab to the guest; the release-input shortcut (Control-Command or Control-Option) hands control back to the host.

Sound — output and input are independent Virtio sound devices; either can be attached without the other. Microphone input asks for macOS microphone permission the first time the guest listens.

Performance — memory ballooning, and nested virtualization on an M3 or later Mac.

Automatic Setup (first boot) — for macOS 27 guests: create the first account (mac with password macvisor by default; the New VM form remembers the last account you used), log in automatically, and enable Remote Login (SSH), skipping Setup Assistant. With Remote Login on, MacVisor installs the MacVisor Agent itself after the first boot and authorises your SSH keys. The settings are ignored once the guest has been provisioned.

NVRAM — for a macOS guest that is shut down: the guest's NVRAM variables, such as boot-args (-v for a verbose boot). A wrong value can keep the guest from booting. macOS 27 currently refuses the private interface this uses, and the section says so instead of showing an empty list; mvz nvram <vm> reports the same.

USB — list devices to capture automatically when they are plugged in while the VM runs, or connect a device on demand from the USB button in the VM window toolbar.

Firmware (Linux guests) — Secure Boot boots only signed kernels; shim-signed distributions work. Turning it off keeps the enrolled keys.

Devices

Toggling an auxiliary device changes the VM's device topology: it needs a restart and discards saved memory state.