HCS

Warning “hcs” mode is experimental

“hcs” option makes use of native virtualization support provided by Windows’ Host Compute System (HCS) API (more info).

An example configuration:

• CLI
• YAML

limactl start --vm-type=hcs --plain --dns 8.8.8.8

# Example to run Ubuntu using vmType: hcs
vmType: hcs
images:
- location: "https://cloud-images.ubuntu.com/releases/resolute/release-20260720/ubuntu-26.04-server-cloudimg-amd64.img"
  arch: "x86_64"
  digest: "sha256:117816726abbdefc5ef3e38902e81a76f1c76c3610e709999d0885f9d5d9b477"
plain: true
dns:
- 8.8.8.8

Caveats

• We tested it works only on Windows 11 (x86_64).
• Only plain mode is supported (no file mount, no dynamic port-forwarding).
• qemu-img is required for the image conversion; see Disk images.
• The user must be a member of the Hyper-V Administrators group; see Setup for HCS driver
• limactl should be run from a shell opened with Administrator privileges.
• Currently, only one instance can run using hcs at a time, beucause the HCN network subnet is fixed and cannot be shared by multiple instances.
• A DNS server has to be specified explicitly.

Disk images

• The hcs driver can only boot from a .vhdx disk image.
• If the image is not a .vhdx (for example .qcow2), Lima automatically converts it to .vhdx by running qemu-img convert -O vhdx.
• Therefore, if you would like to download the image or to pass a disk image which is not .vhdx, qemu-img is required.

Setup for HCS driver

1. Enable virtualization on Windows: Follow the instrunctions in Microsoft guide to enable virtualization on your Windows host.

2. Add yourself to Hyper-V Administrators group: Run the following command on powershell or cmd.exe with Run as administrator:

   net localgroup "Hyper-V Administrators" <user name> /add
   

   Then, restart the terminal or reboot the computer for the changes to take effect.

   To verify that your user account has been added to Hyper-V Administrators group, run:

   net localgroup "Hyper-V Administrators"