Why does my robocopy can´t use more than 2 Gbps? A single procces can use the full potential of the NIC teaming?
I have 2 Win2012R2 Physical Servers with 4 1Gbps LAN adapters each, configured in LACP using Windows NIC Teaming
So, i have 4 Gbps link in each server, pottentially allowing copying files form server to another (SMB) using a full 4 Gbps data-link.
But...
If i use robocopy SOURCE DESTINATION, the copy uses only 99% of one 0,9 Gbps LAN adapter
after i´ve changed the /MT:128, using muti-threaded, i could achive 1,9 Gbps, therefore, 99% of the maximum aggretae of 2 NICs
What i was expecting? That i could see files being copied using the full 4 Gbps theoretical max of the aggregated link
IN the past i saw a lot of limitations like this one, where ArcServe (for instance) could use only one LAN adapter/1 Gbps because it was a single proccess, so a single proccess couldn´t use more than what is being provided by a single NIC
It´s is really true?
Only multi-threaded procces can traspass the 1 Gbps limit and transfer data really aggreagting all LAN adapters?
If so, why does robocopy, even using the /MT:128 parameter, allowing 128 threads, uses only 50% of the aggreaged 4 Gbps link?