Clean up the storage space of the device, export and delete the old sleep data, and expand the storage space.

1. Clean up the storage space of the device: delete unnecessary files, applications or other data to free up more storage space.

2. Export and delete old sleep data: If the device supports the function of exporting sleep data, you can export and save the old sleep data to other devices or cloud storage services, and then delete these data from the device to free up space.

3. Expand the storage space: If the device supports external storage expansion, you can purchase additional memory cards to expand the storage space, and storing some sleep data on the external memory card can reduce the burden on the device itself.