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 datacenter 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 4.1 or Later Features
With vSphere 4.1 or later, you can now also use the following features:
vStorage thin provisioning, which lets you start out with as little disk space as necessary and grow the disk to add space later
Tiered storage, which allows you to distribute virtual disks in the View environment across high-performance storage and lower-cost storage tiers, to maximize performance and cost savings
Local storage on the ESXi host for the virtual machine swap files in the guest operating system
Compatible vSphere 5.0 and 5.1 or Later Features
With vSphere 5.0 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.
You can deploy a desktop pool on a cluster that contains up to 32 ESXi hosts, with certain restrictions.
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 5.5 Update 1 or Later Features
With vSphere 5.5 Update 1 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 32 ESXi hosts.
While supporting VMware features that require shared storage, such as HA, vMotion, and DRS, Virtual SAN eliminates the need for an external shared storage and simplifies storage configuration and virtual machine provisioning activities.
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.