# rsync

Guide for synchronizing files and directories between systems using rsync over SSH.

---

## Local to remote

1.  ### Install

    Ensure rsync is installed on both the local (source) and remote (destination) systems.

    ```sh
    sudo apt update && sudo apt install rsync -y
    ```

2.  ### Basic sync

    Synchronize a local directory to a remote server. The `-a` flag preserves permissions/links, and `-v` provides verbose output.

    ```sh
    rsync -av {{RSYNC_LOCAL_PATH_VAR}} {{USERNAME_VAR}}@{{SERVER_IP_VAR}}:{{RSYNC_REMOTE_PATH_VAR}}
    ```

3.  ### Sync with compression and progress

    Use `-z` to compress data during transfer and `-P` to show a progress bar and allow resuming partial transfers.

    ```sh
    rsync -avzP {{RSYNC_LOCAL_PATH_VAR}} {{USERNAME_VAR}}@{{SERVER_IP_VAR}}:{{RSYNC_REMOTE_PATH_VAR}}
    ```

4.  ### Delete extraneous files

    Use the `--delete` flag to remove files on the destination that no longer exist on the source, keeping them perfectly in sync.

    ```sh
    rsync -av --delete {{RSYNC_LOCAL_PATH_VAR}} {{USERNAME_VAR}}@{{SERVER_IP_VAR}}:{{RSYNC_REMOTE_PATH_VAR}}
    ```

## Remote to local (pull)

1.  ### Pull files

    Download a directory from a remote server to your local machine.

    ```sh
    rsync -av {{USERNAME_VAR}}@{{SERVER_IP_VAR}}:{{RSYNC_REMOTE_PATH_VAR}} {{RSYNC_LOCAL_PATH_VAR}}
    ```

2.  ### Custom SSH port

    If the remote server uses a non-standard SSH port, specify it using the `-e` flag.

    ```sh
    rsync -av -e 'ssh -p 2222' {{USERNAME_VAR}}@{{SERVER_IP_VAR}}:{{RSYNC_REMOTE_PATH_VAR}} {{RSYNC_LOCAL_PATH_VAR}}
    ```

## Maintenance

1.  ### Dry run

    Always perform a dry run before executing a command with `--delete` to see what changes will be made without actually transferring files.

    ```sh
    rsync -av --dry-run {{RSYNC_LOCAL_PATH_VAR}} {{USERNAME_VAR}}@{{SERVER_IP_VAR}}:{{RSYNC_REMOTE_PATH_VAR}}
    ```

2.  ### Exclude files

    Exclude specific files or directories (like `node_modules` or `.git`) from being synchronized.

    ```sh
    rsync -av --exclude '{{PATTERN_VAR}}' {{RSYNC_LOCAL_PATH_VAR}} {{USERNAME_VAR}}@{{SERVER_IP_VAR}}:{{RSYNC_REMOTE_PATH_VAR}}
    ```