This topic describes the considerations that you must pay close attention to when a block gateway transmits data.

Data is uploaded to block gateways in slices. You can customize the slice size. The default slice size is 32 KB. On-premises block gateways cache data based on how frequently the data is read. When an on-premise block gateway needs to read cold data (infrequently read data) but it cannot find the data on the client, it downloads the data from the associated Object Storage Service (OSS) bucket. Downstream transmissions occur.