echo " -o, --output: output image file (default: ${DEST})."
echo " -r, --resync-string: internally used to resync previous made snapshots."
echo " -f, --refresh: try to sync a running snapshot."
echo " -o, --output: output image file (default: ${DEST})."
echo " -r, --resync-string: internally used to resync previous made snapshots."
echo " -f, --refresh: try to sync a running snapshot."