功能

只是想给无人机挂载一个外置硬盘，然后录制数据包到这个外置硬盘里面，方便后续模拟和评估啥的；
这个硬盘是开机挂载，但是录完后直接拆下来，所以不能直接把开机挂载写到fstab里面；

重要参考

想了解一下大家ROS2开机自启动使用的什么方式

挂载和录制脚本

在home目录下建一个bin文件夹，然后创建这个录制脚本

mkdir -p bin
cd bin
nano record_to_mount.sh

脚本内容

#!/bin/bash
set -euo pipefail

# 简易录制脚本（中文注释）
# 使用说明：
#  - 本脚本为简化版，已将必要配置写死到脚本中（部署前请编辑下面的固定项）。
#  - 启动流程：等待 -> 尝试挂载指定设备 -> 若挂载成功，开始 `rosbag record -a` 并按 SIZE_MB 切分文件；若挂载失败则退出不录制。
#  - 注意：挂载通常需要 root 权限，建议通过 systemd 或在含有合适权限的环境下运行。
#  - 设备支持形式：直接设备路径（/dev/sda1）或 UUID=xxxx 或 LABEL=NAME。

# --- 固定配置（部署前请修改这些值） ---
DEVICE="UUID=ABCD-1234"   # 示例：UUID=1234-ABCD 或 /dev/sda1 或 LABEL=MYUSB
MOUNT_POINT="/mnt/record"           # 挂载点目录
OUT_SUBDIR="rosbags"                # 挂载盘内用于保存 bag 的子目录
SIZE_MB=1024                         # 切分大小（MB），默认 1024
WAIT_SECONDS=10                      # 启动后等待秒数
BACKGROUND=${BACKGROUND:-1}          # 1=后台运行；0=前台运行 (可由环境变量覆盖)
DRY_RUN=${DRY_RUN:-0}                # 1=仅打印命令（不执行挂载/录制）

echo "等待 ${WAIT_SECONDS}s，准备挂载..." >&2
sleep "$WAIT_SECONDS"

# Resolve DEVICE to a path mount can use
device_path="$DEVICE"
if [[ "$DEVICE" == UUID=* ]]; then
    uuid=${DEVICE#UUID=}
    device_path="/dev/disk/by-uuid/$uuid"
elif [[ "$DEVICE" == LABEL=* ]]; then
    label=${DEVICE#LABEL=}
    device_path="/dev/disk/by-label/$label"
fi

mkdir -p "$MOUNT_POINT"

if command -v mountpoint >/dev/null 2>&1 && mountpoint -q "$MOUNT_POINT"; then
    echo "Mount point $MOUNT_POINT already mounted." >&2
else
    echo "Attempting mount: $device_path -> $MOUNT_POINT" >&2
    if ! mount "$device_path" "$MOUNT_POINT" 2>/dev/null; then
        echo "Mount failed: $device_path -> $MOUNT_POINT. Aborting recording." >&2
        exit 3
    fi
fi

# 载入 ROS 环境（如果存在），放在挂载成功后执行；失败不致命
hostip=`hostname -I | awk -F " "  '{print $1}'`
if [[ ! -z $hostip ]]; then
  #hostip=192.168.2.20
  echo HOST_IP:$hostip
  export ROS_IP=$hostip
fi

if [ -f /home/visbot/ros_ws/install/setup.bash ]; then
    set +u
    source /home/visbot/ros_ws/install/setup.bash || true
    set -u
elif [ -f /home/visbot/ros_ws/devel/setup.bash ]; then
    set +u
    source /home/visbot/ros_ws/devel/setup.bash || true
    set -u
fi

OUT_DIR="${MOUNT_POINT%/}/$OUT_SUBDIR"
mkdir -p "$OUT_DIR"

timestamp=$(date +"%Y-%m-%d_%H-%M-%S")
outfile_prefix="$OUT_DIR/${timestamp}_record"

cmd=(rosbag record -a --split --size="$SIZE_MB" -O "$outfile_prefix")

if [ "$DRY_RUN" -eq 1 ]; then
    echo "DRY RUN: would mount: $device_path -> $MOUNT_POINT" >&2
    echo "DRY RUN: output dir: $OUT_DIR" >&2
    echo "DRY RUN: command:" >&2
    printf '%q ' "${cmd[@]}"; echo; echo
    exit 0
fi

echo "Starting recording to: $outfile_prefix*.bag (split ${SIZE_MB}MB)" >&2

if [ "$BACKGROUND" -eq 1 ]; then
    logfile="$OUT_DIR/${timestamp}.log"
    nohup "${cmd[@]}" >"$logfile" 2>&1 &
    pid=$!
    echo "$pid" > "$OUT_DIR/${timestamp}.pid"
    echo "Recording started in background (pid: $pid), log: $logfile" >&2
else
    exec "${cmd[@]}"
fi

开机自启动脚本

同样在bin下建立record-rostopics.service文件，内容为

# Example systemd unit to start the recorder at boot.
# Edit the Environment lines and ExecStart path as needed before deploying to the UAV.
[Unit]
Description=Record ROS topics to external mount
After=network-online.target
Wants=network-online.target

[Service]
Type=simple
# Run as root to allow mounting the device. If you mount in fstab, you can change User.
User=root
# 在同一 shell 中先加载 ROS 环境，再运行脚本，确保 rosbag 能找到消息类型与 Master
Environment=BACKGROUND=0
ExecStart=/bin/bash -lc 'source /home/visbot/ros_ws/install/setup.bash 2>/dev/null || true; source /home/visbot/ros_ws/devel/setup.bash 2>/dev/null || true; exec /bin/bash /home/visbot/bin/record_to_mount.sh'
Restart=on-failure
RestartSec=5
TimeoutStartSec=0
# 发送 SIGINT 以便 rosbag 优雅关闭并 flush 文件
KillSignal=SIGINT
TimeoutStopSec=30
# 停止后尝试同步并卸载（忽略错误），避免拔盘时数据未写入
# ExecStopPost=/bin/sync
# ExecStopPost=/bin/umount -l /mnt/record || true

[Install]
WantedBy=multi-user.target

复制到指定目录

 sudo cp ./record-rostopics.service /etc/systemd/system/

尝试重启服务，在命令行分别执行

systemctl daemon-reload
sudo systemctl enable record-rostopics.service
systemctl start record-rostopics.service  # 多次重启测试的话用restart
systemctl status record-rostopics.service

最后一个命令打印

record-rostopics.service - Record ROS topics to external mount
     Loaded: loaded (/etc/systemd/system/record-rostopics.service; disabled; vendor preset: enabled)
     Active: activating (auto-restart) (Result: exit-code) since Sat 2021-01-02 12:37:33 CST; 100ms ago
    Process: 61380 ExecStart=/home/visbot/bin/record_to_mount.sh (code=exited, status=203/EXEC)
   Main PID: 61380 (code=exited, status=203/EXEC)

检查是否成功挂载，敲入df -h，多出了一行

/dev/sda         938G   31G  860G   4% /mnt/record

进入目标目录看是否录制

cd /mnt/record/rosbags
ls

看到类似2021-01-02_16-34-28_record_0.bag.active的文件名就说明成功录制了。