Docker Desktop Settings: Resource Saver and File Sharing Configuration

> multi-container workloads, increase the memory and disk image space allocation - **Resource Saver**. Enable or disable [Resource Saver mode](/manuals/desktop/use-desktop/resource-saver.md), which significantly reduces CPU and memory utilization on the host by automatically turning off the Linux VM when Docker Desktop is idle (i.e., no containers are running). You can also configure the Resource Saver timeout which indicates how long should Docker Desktop be idle before Resource Saver mode kicks in. Default is 5 minutes. > [!NOTE] > > Exit from Resource Saver mode occurs automatically when containers run. Exit > may take a few seconds (~3 to 10 secs) as Docker Desktop restarts the Linux VM. ### File sharing > [!NOTE] > > On Windows, the **File sharing** tab is only available in Hyper-V mode because the files > are automatically shared in WSL 2 mode and Windows container mode. Use File sharing to allow local directories on your machine to be shared with Linux containers. This is especially useful for editing source code in an IDE on the host while running and testing the code in a container. #### Synchronized file shares Synchronized file shares is an alternative file sharing mechanism that provides fast and flexible host-to-VM file sharing, enhancing bind mount performance through the use of synchronized filesystem caches. Available with Pro, Team, and Business subscriptions. To learn more, see [Synchronized file share](/manuals/desktop/features/synchronized-file-sharing.md). #### Virtual file shares By default the `/Users`, `/Volumes`, `/private`, `/tmp` and `/var/folders` directory are shared. If your project is outside this directory then it must be added to the list, otherwise you may get `Mounts denied` or `cannot start service` errors at runtime. File share settings are: - **Add a Directory**. Select `+` and navigate to the directory you want to add. - **Remove a Directory**. Select `-` next to the directory you want to remove - **Apply & Restart** makes the directory available to containers using Docker's bind mount (`-v`) feature. > [!TIP] > > * Share only the directories that you need with the container. File sharing > introduces overhead as any changes to the files on the host need to be notified > to the Linux VM. Sharing too many files can lead to high CPU load and slow > filesystem performance. > * Shared folders are designed to allow application code to be edited > on the host while being executed in containers. For non-code items > such as cache directories or databases, the performance will be much > better if they are stored in the Linux VM, using a [data volume](/manuals/engine/storage/volumes.md) > (named volume) or [data container](/manuals/engine/storage/volumes.md). > * If you share the whole of your home directory into a container, MacOS may > prompt you to give Docker access to personal areas of your home directory such as > your Reminders or Downloads. > * By default, Mac file systems are case-insensitive while Linux is case-sensitive. > On Linux, it is possible to create two separate files: `test` and `Test`, > while on Mac these filenames would actually refer to the same underlying > file. This can lead to problems where an app works correctly on a developer's > machine (where the file contents are shared) but fails when run in Linux in > production (where the file contents are distinct). To avoid this, Docker Desktop > insists that all shared files are accessed as their original case. Therefore, > if a file is created called `test`, it must be opened as `test`. Attempts to > open `Test` will fail with the error "No such file or directory". Similarly, > once a file called `test` is created, attempts to create a second file called > `Test` will fail. > > For more information, see [Volume mounting requires file sharing for any project directories outside of `/Users`](/manuals/desktop/troubleshoot-and-support/troubleshoot/topics.md)

This section focuses on Docker Desktop's Resource Saver mode, which reduces CPU and memory usage when Docker is idle, and its configuration options. It also explains the File Sharing settings, available in Hyper-V mode on Windows, which allow sharing local directories with Linux containers for editing and testing code. Synchronized file shares for faster performance are available with Pro, Team, and Business subscriptions. The default shared directories, adding or removing directories, and the importance of sharing only necessary directories for optimal performance are also discussed. Finally, it highlights MacOS case-insensitivity and its potential impact on Linux container behavior.