lima-vm/lima · error

failed to create new virtio block device config for extra di

Error message

failed to create new virtio block device config for extra disk %#q: %w

What it means

Creating the virtio-block device configuration wrapping the disk attachment via vz.NewVirtioBlockDeviceConfiguration failed; Lima wraps the framework error. This is the last VM-configuration step for the extra disk, so the attachment object was created but the device config could not be built.

Source

Thrown at pkg/driver/vz/vm_darwin.go:608

		logrus.Infof("Mounting disk %#q on %#q", diskName, disk.MountPoint)
		if err = disk.LockForInstance(inst.Dir); err != nil {
			return fmt.Errorf("failed to attach disk %#q: %w", diskName, err)
		}
		extraDiskPath := filepath.Join(disk.Dir, filenames.DataDisk)
		// ConvertToRaw is a NOP if no conversion is needed
		logrus.Debugf("Converting extra disk %#q to a raw disk (if it is not a raw)", extraDiskPath)

		if err = diskUtil.Convert(ctx, raw.Type, extraDiskPath, extraDiskPath, nil, true); err != nil {
			return fmt.Errorf("failed to convert extra disk %#q to a raw disk: %w", extraDiskPath, err)
		}
		extraDiskPathAttachment, err := vz.NewDiskImageStorageDeviceAttachmentWithCacheAndSync(extraDiskPath, false, diskImageCachingMode, vz.DiskImageSynchronizationModeFsync)
		if err != nil {
			return fmt.Errorf("failed to create disk attachment for extra disk %#q: %w", extraDiskPath, err)
		}
		extraDisk, err := vz.NewVirtioBlockDeviceConfiguration(extraDiskPathAttachment)
		if err != nil {
			return fmt.Errorf("failed to create new virtio block device config for extra disk %#q: %w", extraDiskPath, err)
		}
		configurations = append(configurations, extraDisk)
	}

	if err := validateDiskFormat(ciDataPath); err != nil {
		return err
	}
	ciDataAttachment, err := vz.NewDiskImageStorageDeviceAttachment(ciDataPath, true)
	if err != nil {
		return err
	}
	ciData, err := vz.NewVirtioBlockDeviceConfiguration(ciDataAttachment)
	if err != nil {
		return err
	}
	configurations = append(configurations, ciData)

	vmConfig.SetStorageDevicesVirtualMachineConfiguration(configurations)

View on GitHub (pinned to dd909d0973)

Solutions

1. Retry after updating macOS and Lima to the latest versions
2. Reduce the number of attached disks/devices in the VM configuration
3. Report with the wrapped underlying error if it persists on a supported macOS version

if err := startInstance(cfg); err != nil {
    if strings.Contains(err.Error(), "virtio block device config") {
        // retry once after updating macOS/Lima; report the wrapped cause if persistent
    }
}

When it happens

Trigger: vz.NewVirtioBlockDeviceConfiguration(extraDiskPathAttachment) returns an error immediately after a successful attachment creation — essentially only framework-internal failures or invalid attachment state.

Common situations: macOS Virtualization framework version quirks; resource/configuration limits in the VM config reached; rare framework bugs on beta macOS versions.

Related errors

• failed to create disk attachment for extra disk %#q: %w
• failed to create host audio output stream: %w
• failed to get macOS product version: %w
• failed to create a new rosetta directory share caching optio
• %w (set video.display to "default" or "vz" to enable screens

AI-assisted analysis of lima-vm/lima@dd909d0973 (2026-09-01). Data as JSON: /api/errors/f74777476b9b216a. Report an issue: GitHub.