# Disks A disk is what a machine boots, and `machine disks build` makes one. You give it exactly one source. | Source | What it takes | |---|---| | `--binary path` | a static x86_64 executable, wrapped in a small image | | `--image ref` | a Docker image, as a save tar or a name in your local Docker | | `--compose dir` | a Compose project directory and the images its services name | A binary or an image runs as one container. A Compose project runs every service in it. ```bash machine disks build --image myapp:latest app machine disks build --compose ./deploy stack ``` The name defaults to whatever the source is called. Use `--entrypoint` to choose the executable the service runs. Flags go before the name, and the service's own arguments go after a `--`. This one runs `data-race` with the argument `3`: ```bash machine disks build --binary ./data-race race -- 3 ``` ## Building disks on an ARM machine A machine is an x86_64 computer, so a disk holds `linux/amd64` programs, whatever machine you build it on. On a Mac with Apple Silicon or on arm64 Linux, Docker builds and pulls `arm64` images by default, and those cannot run in a machine. `machine disks build` checks every image and refuses one that is not `linux/amd64` before uploading anything. Ask Docker for `linux/amd64`: ```bash docker pull --platform linux/amd64 myapp:latest docker build --platform linux/amd64 -t myapp:latest . DOCKER_DEFAULT_PLATFORM=linux/amd64 docker compose -f ./deploy/compose.yaml build ``` The last one builds a Compose project's images for `linux/amd64`; setting `platform: linux/amd64` on each service does the same. Docker builds them under emulation, which is slower than a native build but works. For `--binary`, compile for x86_64 Linux, for example `GOOS=linux GOARCH=amd64 go build`. ## Disk size By default Machine measures what the disk holds and adds a gigabyte. Use `--size` to set the size you want. Not sure how big it will be? `--dry-run` reports what the disk would hold without building it. To manage your disks: ```bash machine disks list machine disks show app machine disks rename app app-v2 machine disks delete app-v2 ``` Deleting a disk is permanent. Machine refuses to delete one that a run still boots, and `--force` deletes it anyway and takes those runs with it. `machine disks transfers` shows the transfers in progress, and `machine disks cancel` stops one.