I have a SQL system that is doing a large amount of reads to disk at a throughput rate of about 1GB/s at times. During the time there is a lot of disk activity, the ISCSI is translated to over 8GB/s of network receive activity. in this scenario we are using Jumbo frames, so I would assume that there is about 99.1% of efficiency, and we are certainly not seeing that.
Setup: HPE 3PAR SAN VMware virtual machine with dedicated 10GB virtual adapter for ISCSI All the recommended advanced network adapter settings are set on the NIC Using the in-guest Microsoft ISCSI initiator driver and setup - no 3rd party tools We are set up with ISCSI MPIO (round robin with subset) from the single Client side ISCSI IP to two 10GB Array side ISCSI IP/IQNs
Can anyone think of why the Disk reads would be causing such a large amount of Network traffic?
Normally, disks are measured in Bytes (more precisely, Octets) and networks are measured in Bits. Since there is no international standard for those units, it is usually advised to never abbreviate them. In particular, both Byte and Bit are commonly abbreviated as "B", and it is assumed that the meaning is clear from context (e.g. when talking about storage, we never talked about Bits, when talking about networks, we generally talk about Bits).
So, a throughput of 1 GByte/s on the disk is 8 Gbit/s, which matches pretty much exactly what you are seeing on the network.