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Table Of Contents
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,
instant-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.
Requirements and Limitations
The Virtual SAN feature has the following limitations when used in a View deployment:
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This release does not support using the View space-efficient disk format feature, which reclaims disk
space by wiping and shrinking disks.
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Virtual SAN does not support the View Composer Array Integration (VAAI) feature because Virtual
SAN does not use NAS devices.
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Virtual SAN datastores are not compatible with Virtual Volumes datastores for this release.
NOTE Virtual SAN is compatible with the View Storage Accelerator feature. Virtual SAN provides a
caching layer on SSD disks, and the View Storage Accelerator feature provides a content-based cache that
reduces IOPS and improves performance during boot storms.
The Virtual SAN feature has the following requirements:
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vSphere 5.5 Update 1 or a later release.
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Appropriate hardware. For example, VMware recommends a 10GB NIC and at least one SSD and one
HDD for each capacity-contributing node. For specifics, see the VMware Compatibility Guide.
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A cluster of at least three ESXi hosts. You need enough ESXi hosts to accommodate your setup. For
more information, see the vSphere Configuration Maximums document, available from
https://www.vmware.com/support/pubs/vsphere-esxi-vcenter-server-pubs.html.
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SSD capacity that is at least 10 percent of HDD capacity.
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Enough HDDs to accommodate your setup. Do not exceed more than 75% utilization on a magnetic
disk.
Chapter 3 Managing Desktop and Application Pools from a Central Location
VMware, Inc. 39