The Microsoft Networking team has changed the way it supports Network Interface Cards (NICs) for use with Windows Server.
As team member Dan Cuomo explained, starting with Windows Server 2008, “Microsoft qualifies NICs based on the link speed of the adapter. (Microsoft test) requirements enforced (as designed by manufacturer).”
This approach means that some NIC vendors have tested speed rather than actual performance. But today, servers are being required to do all kinds of intensive I/O work, including running Microsoft Storage Spaces Direct’s software-defined storage product, which is increasingly used in hyperconverged infrastructure.
Microsoft argues that actual speed is not an indication of how a NIC will perform in a server that is essentially being asked to act as a shared storage array. So with Microsoft’s outdated certification, customers weren’t aware of the scenarios in which the NIC might struggle to deal with it.
After Windows Server 2022 debuted, Microsoft realized that its approach of assuming that the faster NICs were the best NICs was insufficient.
Cuomo said the operating system “increased the number of support instances which thwarted ‘unsupported’ support claims even though the device is supported”.
Microsoft’s response is the NIC certification system that evaluates performance based on whether a device can operate in three roles.
- Calculate the traffic. Traffic originating from or destined for a virtual machine (VM).
- Storage movement: Traffic using Server Message Block (SMB), such as live storage spaces and direct SMB-based migration.
- management movement: Traffic to and from outside the local group. For example, traffic for storage replicas and traffic that administrators use to manage groups such as Remote Desktop, Windows Admin Center, and Active Directory.
The new certificate system for NICs is not compatible with Microsoft products or applications.
Cuomo wrote: “This change is an end to the dangerous wording ‘sorry, your configuration is not supported’.” “We hear feedback about how frustrated you are when you just contact support for a certified device and discover that the adapter is not supported the way it is used.”
Not all NICs are approved for a Microsoft role. In this case, Cuomo said, it might be a good idea to support apps with different traffic profiles. ®