vSphere 5.5 introduced a new feature called Virtual SAN (vSAN). This feature allows utilizing a host's local storage to create a shared distributed storage for VM placement.
vSAN is a software-based solution built into ESXi; it's scalable and easy to configure and manage.
vSAN requires a license separate from vSphere and vCenter. The feature is licensed on a per-CPU basis.
The minimum infrastructure requirements for vSAN are:
Also, it is recommended to:
Use 10 Gbps NICs.
Have a VMkernel vSAN adapter on every physical NIC.
Have a 1:10 ratio between SSD and HDD capacity.
Hardware RAID is not required and it's better to have just a bunch of disks without any hardware RAID configured. Create more disk groups of a smaller size rather than less...