Disks

This guide explains how to manage Lima disks: standalone raw/qcow2 block devices that persist independently of any instance.

Additional Disks (limactl disk)

Lima disks can be shared across instances and survive instance deletion.

Listing disks

limactl disk list
# or the short alias:
limactl disk ls

Creating a disk

limactl disk create NAME --size SIZE [--format qcow2|raw]

The supported formats are qcow2 (default) and raw.

Example – create a 20 GiB disk named data:

limactl disk create data --size 20GiB

Attaching a disk to an instance

• YAML
• CLI

additionalDisks:
- name: data
  format: true     # format the disk on first use
  fsType: ext4     # filesystem to create when format is true

limactl edit <instance> --set '.additionalDisks += [{"name":"data"}]'

Resizing an additional disk

limactl disk resize NAME --size NEW-SIZE

Deleting a disk

limactl disk delete NAME [NAME...]

Note: A disk cannot be deleted while attached to a running instance. Stop the instance first or use --force.

Resizing the VM’s primary disk

Starting with v1.1, Lima supports editing the disk size of an existing instance using the --disk flag with the limactl edit command. This is the recommended and simplest way to resize your VM disk.

limactl edit <vm-name> --disk <new-size>

Example for 20GB:

limactl edit default --disk 20

Note:

• Increasing disk size is supported, but shrinking disks is not recommended.
• The instance may need to be stopped before editing disk size.

Attach host block devices

Lima can attach a host block device directly to the guest.

Example configuration:

• CLI
• YAML

# hdiutil attach -nomount ram://65536   # create a ramdisk to test without a USB key or real drive
limactl start --vm-type=vz --block-device=/dev/disk4 template:default

# hdiutil attach -nomount ram://65536   # create a ramdisk to test without a USB key or real drive
limactl start --vm-type=vz --block-device=/dev/rdisk4 template:default

vmType: "vz"
blockDevices:
- /dev/disk4
- /dev/rdisk5

The --block-device flag can be specified multiple times to attach multiple host block devices.

Sudoers setup

Opening a host block device requires a privileged helper on macOS. Generate and install the Lima sudoers file before using --block-device:

limactl sudoers >etc_sudoers.d_lima
less etc_sudoers.d_lima
sudo install -o root etc_sudoers.d_lima /etc/sudoers.d/lima
rm etc_sudoers.d_lima

limactl sudoers emits the entries needed for both vmnet helpers and block-device helpers.

Notes

• The configured path must be an absolute host path under /dev, e.g. /dev/disk4, /dev/rdisk4, /dev/sdc, etc.
• The guest will see a corresponding virtio /dev/disk/by-id/virtio-disk4 block device attached, you are responsible for partitioning, formatting, and mounting any filesystems on the block devices
• Avoid mounting filesystems on shared block devices on both host and guest at the same time, it will cause corruption as most filesystems are not designed to be shared by multiple live kernels at once.