I´ve changed some stuff compared to the original first post:
For testing, I´m using a HP Proliant ML310e Gen8 v2 - Server. It good 4x 1TB HDD connected to the buildin HP Smart Array B120i, 1x 160GB SSD connected to the SATA-Port on what normally the second ODD would go to. The Smart Array B120i detects it as normal drive and allows me to configure it.
I´ve used the Smart Array Offline Configuration Tool (which is onboard with the ILO) to confire 5x Single LUNs (4x the 1TB Disks and 1x the SSD). It is recommended to run the Smart Array Controller in its normal mode instead of AHCI or anything because the system fans will slow down to 5% (instead of running 29% when using AHCI - Setting in BIOS). At the moment, the Server has only 4GB of RAM so I could not install VMware ESX 5.5. Instead, I used VMware ESXi 5.1.0 Build 14483097 (Update 2) with a customized HP image http://h18004.www1.hp.com/products/servers/software/vmware/esxi-image.html The customized images are directly hosted by VMware, HP ist just pointing to VMware.
I had to use the RDM - trick to add the HDD to the VM. A nice trick for getting the correct identifier for assigning to a RDM-file s going to the server configuration -> Storage -> Devices, searching the desired disk and make a right-click and select "Copy Identifier to clipboard":
I also changed the virtual Network adapter to use the VMware VMXNET 3:
In addition to allow external USB-Disks or other USB-Devices added to the VM, I added an USB Controller (I used the EHCI+UHCI):
If you want to connect the USB-Disks to the VM, you have to connect the hardware to your server, then go to the settings of the VM and add the USB-Devices to the VM.
One important thing to the VMware ESX 5.5:
I´m using VMware ESXi 5.1 because this edition allows me to upgrade the VM-Hardware to vmx-09. When you are using VMware ESXi 5.5, you can also upgrade the VM-Hardware even to version 10, but then you can´t do any changes to the VM-hardware with only the vSphere Client and without the vSphere Server (or the VM appliance).
Because I´m using the VMXNET 3 network adapter it presents to the VM an 10 GBit ethernet adapter. The server just has 2x 1GBit adapters, but with VMware I can use "link aggregation" (http://en.wikipedia.org/wiki/Link_aggregation) to get higher speeds with different clients at the same time.
The VM is sized relatively small, but still works fine with good speed results:
When idle (and only running Plex and PlexConnect):
When copying various files to a volume:
After some testing with the network adapter VMXNET3 there were some trouble: The Webinterface was working fine, but the SMB-Connection between DSM and Windows Server 2012 R2 seems buggy... I don´t know why, I didn´t look into logs or anything, I just switched back ot the E1000 - Adapter... With that booted, the SMB-Connection was working fine again.