It is important to know that you can use several storage access protocols for your data. Below is a short summary of all the protocols vSphere v7.0 supports:
Local and network storage
- DAS (Directly-attached Disks
- vSAN will transform internal storage of your ESXi host into shared storage
- NFS 3 and NFS 4.1
- SCSI, IDE, SATA, USB, SAS, flash and NVMe are supported
Fibre Channel storage
- High-speed network to high-performance storage devices
- Your host will need HBA adapters (Host-Bus-Adapters)
iSCSI storage / storage devices or LUN’s
- Hardware iSCSI will connect the host to storage via a third-party adapter
- Software iSCSI will connect the host to storage via a software-based iSCSI initiator in the VMkernel.
Shared Serial Attached SCSI (SAS)
- Stores virtual machines on direct-attached SAS storage systems
- Usually network based storage
VAAI
- APi’s that help arrays to integrate with vSphere for offloading certain storage operations to an array
vSphere API for multipathing
- Known as Pluggable Storage Architecture (PSA) which uses APIs which allow storage partners to create and deliver multipathing and load-balancing plugins that are optimized for each array
