From the knowledge base, the relevant points are:
- USB Copy supports copying between your Synology NAS and external USB/SD storage devices. When the USB/SD device is inserted again, the NAS will recognize the matched device and apply the same copy settings. [12], [13]
- To run a task, you can:
- click Run on the management interface,
- press the Copy button on supported models,
- or plug in the USB/SD device to your Synology NAS with Copy data whenever the USB/SD storage device is plugged in enabled. [15], [16]
- If you are using the hardware Copy button, note that:
- the Copy Button tab only works with USB devices inserted to the frontal USB port,
- the hardware Copy button does not work with USB/SD devices with multiple disk partitions, and
- when a USB/SD device is already matched with an existing task, you will only run the matched task by pressing the hardware Copy button. [10], [11]
- USB Copy only allows recognized file systems such as FAT32, NTFS, ext3, ext4, and exFAT. [12], [13]
- For some older devices, the USB Copy feature had limitations: on the DS-101g+, USB Copy function only supports USB disks with FAT32 file system. [2]
So, based on the knowledge base, the first things to check are:
1. The device is a supported USB/SD storage type and uses a recognized file system. [12], [13]
2. The correct task exists and the device is matched to it. [10], [11], [12], [13]
3. If you want auto-start on insertion, Copy data whenever the USB/SD storage device is plugged in is enabled. [15], [16]
4. If you use the hardware Copy button, make sure the device is on the front USB port and does not have multiple partitions. [10], [11]
The knowledge base does not provide any more detailed fix steps beyond these points.
Sources used: [10], [12], [13], [15], [16], [2]