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Managing Finch Storage

Disk Mounts

To allow containers and container image builds to access files from the local workstation within the virtual machine, a users home directory (on macOS this is /Users/<username>) is automatically mounted into the machine by Lima.

To demonstrate this, in an empty directory on the workstation you can create a hello file, and then mount it into the container with the --volume command.

touch hello

finch run \
   --volume $PWD:/data \
   public.ecr.aws/amazonlinux/amazonlinux:2 \
   ls /data

You should see the file you just created.

hello

Adding additional disk mounts

For users wanting to mount additional directories in the virtual machine, they can specify additional mounts in the Finch Configuration.

  1. Open the Finch configuration in a text editor ~/.finch/finch.yaml and add the relevant paths for the local directory on your workstation.

    cpus: 3
    memory: 4GiB
    additional_directories:
      - "/Volumes/test"
    
  2. Restart the virtual machine to pick up the changes in the mounts.

    finch vm stop
    finch vm start
    
  3. Once the virtual machine has been restarted you can test this mount. First create a temporary directory and file in this new disk location.

    mkdir /Volume/test/testdir
    touch /Volume/test/testdir/hello
    

    Then mount the volume into a new container.

    finch run \
       --volume /Volume/test/testdir:/data \
       public.ecr.aws/amazonlinux/amazonlinux:2 \
       ls /data
    

    You should see the file you just created.

    hello
    

Disk Mount Technology

By default the disk is mounted into the virtual machine using sshfs. For users running macOS 13 or later, if you switch to Apple's Virtualization Framework in the Finch Configuration, the disk mounts will instead leverage the more performant virtiofs.

  1. Open the Finch configuration in a text editor ~/.finch/finch.yaml and add the key vmType with the value vz.

    cpus: 3
    memory: 4GiB
    vmType: vz
    
  2. Restart the virtual machine to pick up the changes in the virtualization technology.

    finch vm stop
    finch vm start
    

Disk Size

By default the Finch virtual machine will have a disk capacity of 50GB, even though you may have more disk space available on the local workstation. As you start to build container images and run containers, this disk space may reach capacity.

To free up disk space you can delete stale container image layers with:

finch image prune

You can also free up disk by delete all container images without a container attached with:

finch image prune --all

Increasing the size of the Data Disk

To expand the virtual machine disk size above 50GB, you can dive into the underlying virtualization configuration and increase the capacity.

  1. First make sure the virtual machine has been stopped

    finch vm stop
    
  2. Next resize the virtual machine using the qemu-img resize command. This example command increases the disk space by a further 100GB, but this value can be adjusted to suit.

    /Applications/Finch/lima/bin/qemu-img resize /Applications/Finch/lima/data/_disks/finch/datadisk +100G
    
  3. Next start back up the virtual machine

    finch vm start
    
  4. Finally you need to get a shell into the virtual machine to resize the underlying partition.

    export LIMA_HOME=/Applications/Finch/lima/data
    
    /Applications/Finch/lima/bin/limactl shell finch sudo bash -c "growpart /dev/vdb 1"
    /Applications/Finch/lima/bin/limactl shell finch sudo bash -c "resize2fs /dev/vdb1"
    
  5. To validate the change has been successful, with one last shell into the virtual machine, checks the disk size with df -h.

    export LIMA_HOME=/Applications/Finch/lima/data
    
    /Applications/Finch/lima/bin/limactl shell finch df -H