6.7

The PMem datastore is used to store virtual NVDIMM devices and
traditional virtual disks of a VM. The VM home directory with the vmx and
vmware.log files cannot be placed on the PMem datastore.
PMem Access Modes ESXi exposes persistent memory to a VM in two different modes. PMem-
aware VMs can have direct access to persistent memory. Traditional VMs
can use fast virtual disks stored on the PMem datastore.
Direct-Access Mode In this mode, a PMem region can be presented to a VM as a virtual non-
volatile dual in-line memory module (NVDIMM) module. The VM uses the
NVDIMM module as a standard byte-addressable memory that can persist
across power cycles.
You can add one or several NVDIMM modules when provisioning the VM.
The VMs must be of the hardware version ESXi 6.7 and have a PMem-
aware guest OS. The NVDIMM device is compatible with latest guest OSes
that support persistent memory, for example, Windows 2016.
Each NVDIMM device is automatically stored on the PMem datastore.
Virtual Disk Mode This mode is available to any traditional VM and supports any hardware
version, including all legacy versions. VMs are not required to be PMem-
aware. When you use this mode, you create a regular SCSI virtual disk and
attach a PMem VM storage policy to the disk. The policy automatically
places the disk on the PMem datastore.
PMem Storage Policy To place the virtual disk on the PMem datastore, you must apply the host-
local PMem default storage policy to the disk. The policy is not editable.
The policy can be applied only to virtual disks. Because the VM home
directory does not reside on the PMem datastore, make sure to place it on
any standard datastore.
After you assign the PMem storage policy to the virtual disk, you cannot
change the policy through the VM Edit Setting dialog box. To change the
policy, migrate or clone the VM.
The following graphic illustrates how the persistent memory components interact.
vSphere Storage
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