VMware Virtual Storage Area Network (vSAN), was introduced in vSphere 5.5. vSAN is VMware's solution for customers that want software-defined, hyper-converged storage. By installing local drives in your ESXi hosts and purchasing vSAN licensing, you can create a highly available VMware solution that doesn't rely on an external storage array.
vSAN is a very interesting technology and would require a dedicated book to fully explore, so we will just cover the basics here. Hardware-wise, vSAN requires at least one flash disk for caching and at least one storage disk per ESXi host. In a hybrid vSAN, the storage disk will be a spinning disk. In an all flash vSAN, the storage disk will be a flash disk.
vSAN also requires an independent vSAN license, either Standard, Advanced, or Enterprise. If you want to run vSAN with deduplication, compression, and erasure coding, you must have an Advanced or Enterprise license.
Once you have configured vSAN, you will have a datastore presented...