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 board