命令是不是写错了
参考下：
./br backup db --pd "pd_ip:pd_port" --storage "s3://access_key:secret_key@endpoint/bucket_name" --ratelimit 60 --log-file backup.log
Here, “pd_ip:pd_port” is the address of your PD server, “access_key” and “secret_key” are the access key and secret key of your MinIO account, “endpoint” is the endpoint of your MinIO server, and “bucket_name” is the name of the bucket you created for backup.
The “–ratelimit” option specifies the maximum transfer rate in MB/s, and the “–log-file” option specifies the path to the log file.