Emulating an SSD Virtual Disk in Nested ESXi like VMware Fusion, Workstation and

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　　So the solution is actually quite simpleand it is just an advanced setting in the Virtual Machine's configuration file(VMX) which can also be appended to using either the vSphere Web Client,vSphere C# Client or the vSphere API. This setting is only supported on VirtualMachines that is running virtual hardware 8 or greater. To configure a specificvirtual disk to appear as an SSD, you just need to add the following:


　　scsiX:Y.virtualSSD = 1
　　where X is the controller ID and the Y isthe disk ID of the Virtual Disk.

　　

　　This configuration presents to the guestOSthe mediumRotationRate field of the SCSI inquiry pages0xB1 and sets the value to 1 and the guests will then report it as asolid-state device. As you can see, this can benefit more than just runningNested ESXi, you can also do various testing on other guestOSes that yourequire a "fake" SSD device.

Note: Though you can emulate an SSD device, it is no substitute for anactual SSD device and any development or performance tests done in a simulatedenvironment should also be vetted n a real SSD device, especially when it comesto performance.

It is also important to note that reporting of an SSD device will highly dependon the guestOS, here is a high level table on how some of the common guestOSesrecognize SSD devices.

GuestOS	SSD Reporting
Windows 8	IDE, SCSI and SATA disks can be recognized as SSDs
Windows 7	IDE and SATA disks can be recognized SSD, but SCSI as mechanical
Linux (Ubuntu & RHEL)	IDE, SCSI and SATA disks can be recognized as SSDs
Mac OS X	SATA can be recognized as SSDs, but IDE and SCSI as mechnical

　　
Here is a screenshot of a Nested ESXi host with an emulated SSD device:

　　Here is a screenshot of the new Windows 8.1Preview with an emulated SSD device:

　　Note: Though I demonstrated this usingvSphere, this also works for VMware Fusion (tested this personally),Workstation and Player. The only requirement is that you are running virtualhardware 8 or greater and that your guestOS supports reporting SSD device.