M.2 is a solid-state drive (SSD) form factor primarily used as an operating system boot solution however depending on the endurance of the M.2 drives, they may also be suitable for read-intensive or mixed workloads.Lenovo ThinkSystem servers support M.2 drives in one of three ways, depending on the server selected:- One or two drives, mounted in an M.2 adapter, vertically in a dedicated slot- Two or four drives, mounted horizontally in an M.2 adapter- Installed directly on the system boardOne example is the Dual M.2 Adapter, as shown in the following figure, with one 128GB M.2 drive partially inserted. The second M.2 drive is installed on the other side of the adapter.