6.2

Using Virtual SAN for High-Performance Storage and Policy-Based
Management
VMware Virtual SAN is a software-defined storage tier, available with vSphere 5.5 Update 1 or a later
release, that virtualizes the local physical storage disks available on a cluster of vSphere hosts. You specify
only one datastore when creating an automated desktop pool or an automated farm, 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 implements a policy-based approach to storage management. When you use Virtual SAN,
View defines virtual machine storage requirements, such as capacity, performance, and availability, in the
form of default storage policy profiles, which you can modify. Storage is provisioned and automatically
configured according to the assigned policies. You can use Virtual SAN for linked-clone desktop pools, full-
clone desktop pools, or an automated farm.
Each virtual machine maintains its policy regardless of its physical location in the cluster. 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 load-balances to meet the policies of each virtual
machine.
While supporting VMware features that require shared storage, such as HA, vMotion, and DRS, Virtual
SAN eliminates the need for an external shared storage infrastructure and simplifies storage configuration
and virtual machine provisioning activities.
IMPORTANT The Virtual SAN feature available with vSphere 6.0 and later releases contains many
performance improvements over the feature that was available with vSphere 5.5 Update 1. With vSphere 6.0
this feature also has broader HCL (hardware compatibility) support. Also, VMware Virtual SAN 6.0
supports an all-flash architecture that uses flash-based devices for both caching and persistent storage.
Virtual SAN Workflow in View
1 Use vCenter Server 5.5 Update 1 or a later release to enable Virtual SAN. For more information about
Virtual SAN in vSphere 5.5 Update 1, see the vSphere Storage document. For more information about
Virtual SAN in vSphere 6 or later, see the Administering VMware Virtual SAN document.
2 When creating an automated desktop pool or an automated farm in View Administrator, under Storage
Policy Management, select Use VMware Virtual SAN, and select the Virtual SAN datastore to use.
After you select Use VMware Virtual SAN, only Virtual SAN datastores are displayed.
Default storage policy profiles are created according to the options you choose. For example, if you
create a linked-clone, floating desktop pool, a replica disk profile and an operating system disk profile
are automatically created. If you create a linked-clone, persistent desktop pool, a replica disk profile
and a persistent disk profile are created. For an automated farm, a replica disk profile is created. For
both types of desktop pools and automated farms, a profile is created for virtual machine files.
3 To move existing View Composer desktop pools from another type of datastore to a Virtual SAN
datastore, in View Administrator, edit the pool to deselect the old datastore and select the Virtual SAN
datastore instead, and use the Rebalance command. This operation is not possible for automated farms
because you cannot rebalance an automated farm .
4 (Optional) Use vCenter Server to modify the parameters of the storage policy profiles, which include
things like the number of failures to tolerate and the amount of SSD read cache to reserve.
The names of the policies are OS_DISK (for operating system files), PERSISTENT_DISK (for user data
files), REPLICA_DISK (for replicas), and VM_HOME (for virtual machine files such as .vmx and .vmsn
files). Changes to the policy are propagated to newly created virtual machines and to all existing virtual
machines in the desktop pool or the automated farm.
Chapter 15 Reducing and Managing Storage Requirements
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