6.5.1

Table Of Contents
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Binding and Unbinding Virtual Volumes to Protocol Endpoints
At the time of creation, a virtual volume is a passive entity and is not immediately ready for I/O. To
access the virtual volume, ESXi or vCenter Server send a bind request.
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Virtual Volumes Datastores
A Virtual Volumes (VVol) datastore represents a storage container in vCenter Server and the
vSphere Web Client.
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Virtual Volumes and VM Storage Policies
A virtual machine that runs on a Virtual Volumes datastore requires a VM storage policy.
Virtual Volumes
Virtual volumes are encapsulations of virtual machine files, virtual disks, and their derivatives.
Virtual volumes are stored natively inside a storage system that is connected to your ESXi hosts through
Ethernet or SAN. They are exported as objects by a compliant storage system and are managed entirely
by hardware on the storage side. Typically, a unique GUID identifies a virtual volume. Virtual volumes are
not preprovisioned, but created automatically when you perform virtual machine management operations.
These operations include a VM creation, cloning, and snapshotting. ESXi and vCenter Server associate
one or more virtual volumes to a virtual machine.
The system creates the following types of virtual volumes for the core elements that make up the virtual
machine:
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Data-VVol. A data virtual volume that corresponds directly to each virtual disk .vmdk file. As virtual
disk files on traditional datastores, virtual volumes are presented to virtual machines as SCSI disks.
Data-VVols can be either thick or thin provisioned.
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Config-VVol. A configuration virtual volume, or a home directory, represents a small directory that
contains metadata files for a virtual machine. The files include a .vmx file, descriptor files for virtual
disks, log files, and so forth. The configuration virtual volume is formatted with a file system. When
ESXi uses the SCSI protocol to connect to storage, configuration virtual volumes are formatted with
VMFS. With NFS protocol, configuration virtual volumes are presented as an NFS directory. Typically,
it is thin provisioned.
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Swap-VVol. Created when a VM is first powered on. It is a virtual volume to hold copies of VM
memory pages that cannot be retained in memory. Its size is determined by the VM’s memory size. It
is thick provisioned by default.
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Snapshot-VVol. A virtual memory volume to hold the contents of virtual machine memory for a
snapshot. Thick provisioned.
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Other. A virtual volume for specific features. For example, a digest virtual volume is created for
Content-Based Read Cache (CBRC).
Typically, a VM creates a minimum of three virtual volumes, data-VVol, config-VVol, and swap-VVol. The
maximum depends on how many virtual disks and snapshots reside on the VM.
vSphere Storage
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