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Table Of Contents
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Protocol Endpoints
Although storage systems manage all aspects of virtual volumes, ESXi hosts have no direct access
to virtual volumes on the storage side. Instead, ESXi hosts use a logical I/O proxy, called the
protocol endpoint, to communicate with virtual volumes and virtual disk files that virtual volumes
encapsulate. ESXi uses protocol endpoints to establish a data path on demand from virtual
machines to their respective virtual volumes.
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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 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:
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.
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.
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.
vSphere Storage
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