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

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.