To limit the bandwidth usage during S3 transfers with s3cmd, you can use the --limit-rate option. This option allows you to specify the maximum transfer rate in kilobytes per second.
Here's an example command that limits the bandwidth usage to 100KB/s:
s3cmd --limit-rate=100 put local_file s3://bucket_name/
This will upload the local_file to the specified S3 bucket, limiting the transfer rate to 100KB/s.
Similarly, you can use the --limit-rate option with other s3cmd commands such as get and sync to limit the bandwidth usage for downloading or synchronizing files with S3.
Note that the --limit-rate option is not precise and actual transfer rates may vary. It's important to experiment with different values to find the optimal bandwidth limit for your specific requirements.