Microsoft has put out a paper <https://www.nextplatform.com/2021/05/12/microsoft-does-the-math-on-azure-datacenter-switch-failures/> detailing its experiences with the reliability of various vendors’ switches within its Azure data centres. It has a total of over 180,000 switches, and many of them are running “SONiC”, which is a Microsoft-developed Linux variant as an alternative to the vendors’ own proprietary switch OSes. The adoption of SONiC made a major difference to the reliability of the switches: ... in the aggregate, the switches in the Azure network had a 98 percent uptime during those three months, and if Microsoft moved to SONiC on all of its machines, that would boost that to around 99 percent. And if Microsoft is not doing that, we suspect that SONiC has some scale and performance issues. In the future we may be writing about how Microsoft tossed out all other NOSes, but that is not what is happening now, and we suspect for good reasons.