vSphere lets you virtualize disk volumes and file systems so that you can manage and configure storage without having to consider where the data is physically stored.
Fibre Channel SAN arrays, iSCSI SAN arrays, and NAS arrays are widely used storage technologies supported by vSphere to meet different data center storage needs. The storage arrays are connected to and shared between groups of servers through storage area networks. This arrangement allows aggregation of the storage resources and provides more flexibility in provisioning them to virtual machines.
Compatible vSphere 5.5 Update 2 or Later Features
With vSphere 5.5 Update 2 or a later release, you can use Virtual SAN, which virtualizes the local physical solid-state disks and hard disk drives available on ESXi hosts into a single datastore shared by all hosts in a cluster. Virtual SAN provides high-performance storage with policy-based management, so that you specify only one datastore when creating a desktop pool, and the various components, such as virtual machine files, replicas, user data, and operating system files, are placed on the appropriate solid-state drive (SSD) disks or direct-attached hard disks (HDDs).
Virtual SAN also lets you manage virtual machine storage and performance by using storage policy profiles. If the policy becomes noncompliant because of a host, disk, or network failure, or workload changes, Virtual SAN reconfigures the data of the affected virtual machines and optimizes the use of resources across the cluster. You can deploy a desktop pool on a cluster that contains up to 20 ESXi hosts.
The Virtual SAN feature available with vSphere 6.0 and later releases contains many performance improvements. With vSphere 6.0 this feature also has broader HCL (hardware compatibility) support. For more information about Virtual SAN in vSphere 6 or later, see the Administering VMware Virtual SAN document.
Virtual SAN is compatible with the View storage accelerator feature but not with the space-efficient disk format feature, which reclaims disk space by wiping and shrinking disks.
With vSphere 5.5 update 2 or a later release, you can use the following features:
With the View storage accelerator feature, you can configure ESXi hosts to cache virtual machine disk data.
Using this content-based read cache (CBRC) can reduce IOPS and improve performance during boot storms, when many machines start up and run anti-virus scans at the same time. Instead of reading the entire OS from the storage system over and over, a host can read common data blocks from cache.
If remote desktops use the space-efficient disk format available with vSphere 5.1 and later, stale or deleted data within a guest operating system is automatically reclaimed with a wipe and shrink process.
Replica disks must be stored on VMFS5 or later datastores or NFS datastores. If you store replicas on a VMFS version earlier than VMFS5, a cluster can have at most eight hosts. OS disks and persistent disks can be stored on NFS or VMFS datastores.
Compatible vSphere 6.0 or Later Features
With vSphere 6.0 or a later release, you can use Virtual Volumes (VVols). This feature maps virtual disks and their derivatives, clones, snapshots, and replicas, directly to objects, called virtual volumes, on a storage system. This mapping allows vSphere to offload intensive storage operations such as snapshoting, cloning, and replication to the storage system.
Virtual Volumes also lets you manage virtual machine storage and performance by using storage policy profiles in vSphere. These storage policy profiles dictate storage services on a per-virtual-machine basis. This type of granular provisioning increases capacity utilization. You can deploy a desktop pool on a cluster that contains up to 32 ESXi hosts.
Virtual Volumes is compatible with the View storage accelerator feature but not with the space-efficient disk format feature, which reclaims disk space by wiping and shrinking disks.
Instant clones do not support Virtual Volumes.