Noticed what is likely a cut & paste error. Need to skim the S3Storage class at least, and make sure log msgs are going to the right place. Ex:

{{ if (ms3_server_error(creds))
logger->log(LOG_WARNING, "S3Storage::putObject(): failed to PUT, server says '%s'. bucket = %s, key = %s.",
ms3_server_error(creds), bucket.c_str(), destKey.c_str());
else
logger->log(LOG_ERR, "S3Storage::putObject(): failed to PUT, got '%s'. bucket = %s, key = %s.",
s3err_msgs[s3err], bucket.c_str(), destKey.c_str());}}

I can't think of a reason one should go to warning, one should go to err, it's the same error msg.