6.0.1

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After you set up a virtual ash resource, the total available capacity can be used and consumed by both
ESXi hosts as host swap cache and virtual machines as read cache.
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You cannot choose individual ash devices to be used for either swap cache or read cache. All ash
devices are combined into a single ash resource entity.
Set Up Virtual Flash Resource
You can set up a virtual ash resource or add capacity to existing virtual ash resource.
To set up a virtual ash resource, you use local ash devices connected to your host. To increase the capacity
of your virtual ash resource, you can add more devices, up to the maximum number indicated in the
Conguration Maximums documentation. An individual ash device must be exclusively allocated to the
virtual ash resource and cannot be shared with any other vSphere service, such as Virtual SAN or VMFS.
Procedure
1 In the vSphere Web Client, navigate to the host.
2 Click the Manage tab and click .
3 Under Virtual Flash, select Virtual Flash Resource Management and click Add Capacity.
4 From the list of available ash devices, select one or more devices to use for the virtual ash resource
and click OK.
Under certain circumstances, you might not be able to see ash devices on the list. For more
information, see the Troubleshooting Flash Devices section in the vSphere Troubleshooting
documentation.
The virtual ash resource is created. The Device Backing area lists all devices that you use for the virtual
ash resource.
What to do next
You can use the virtual ash resource for cache conguration on the host and Flash Read Cache
conguration on virtual disks. In addition, I/O caching lters developed through vSphere APIs for I/O
Filtering might require the virtual ash resource.
You can increase the capacity by adding more ash devices to the virtual ash resource.
Remove Virtual Flash Resource
You might need to remove a virtual ash resource deployed on local ash devices to free the devices for
other services.
You cannot remove a virtual ash resource if it is congured with host swap cache or if the host has virtual
machines congured with Flash Read Cache that are powered on.
Procedure
1 In the vSphere Web Client, navigate to the host that has virtual ash congured.
2 Click the Manage tab and click .
3 Under Virtual Flash, select Virtual Flash Resource Management and click Remove All.
After you remove the virtual ash resource and erase the ash device, the device is available for other
operations.
vSphere Storage
138 VMware, Inc.