aSAN (virtual storage): aSAN is a software-defined distributed storage system that can run on universal servers. It integrates storage resources within a cluster to provide block storage services externally, HCI guest OS can use the proprietary storage protocol to connect to aSAN in the cluster to enjoy optimal performance and availability.

Based on the type of disks that make up the virtual storage, virtual storage can be classified into all-flash volumes and hybrid volumes. HCI virtual storage all-flash volume refers to a virtual storage setup where all disks are SSDs. In this scenario, there is no need to configure cache disks, you can deploy all SSDs as data disks. All-flash volumes are suitable for scenarios with high performance requirements. HCI virtual storage hybrid volume refers to a virtual storage volume created by combining SSD cache disks and HDD data disks. In this setup, the SSDs are used as cache disks, while the HDDs are deployed as data disks.

External storage: External storage refers to storage devices connected to the HCI platform, typically used for storing virtual machines and backup virtual machines. External storage supports the following types: FC iSCSI and NFS.

The following is a schematic diagram of the I/O data flow for external storage.

Local storage: Local storage refers to the disks that are built into an HCI host. These disks can only be accessed by that host and cannot be shared with other hosts.