IBM Flash Cache, Flash Caching, and vMotion

Hello again!

This is one issue I am in the midst of running into.

We are doing a proof of technology (PoT) with two different vendors and sampling some Flash Cache in the environment.  Initially we were able to spec a IBM 3650 M4 with a Fast Fusion-IO PCI-E Flash drive (365 GB).  This is also testing the IBM Flash Cache software (IO-Turbine) as part of the PoT.

The install of the plug-in and the OVA went pretty well other than needing to install it to the same host that was supposed to be in Maintenance Mode to install the OVA.  We could enable the Host Based or Guest Based caching pretty seemlessly, however I didn't care for the web GUI interface as it didn't refresh and you manually have to add the VMs into the caching manually.  Not really wanting to do that for every VM in the environment as I just want to set it and almost forget it.  The speeds are amazing VMware-IO-Analyzer returns in excess of 50K IOPS (28k Write 21K Read) for the VM and latency > 1 ms. 

Now for the issue I am seeing.   I am moving a VM (Powered Down) created in this Flash based environment to a non-flash based environment using the standard PowerShell command

get-vm <vmname> | move-vm -location <dest_server> -datastore <Test_NFS>

It migrates with no issue and moves disk and compute.  The problem is in the power up.
Status: Failed to start the Virtual Machine. 

  • An error was received from the ESX host while powering on VM <NAME>
  • Failed to start the virtual machine.
  • Module DevicePowerOn power on failed.
  • Unable to create virtual SCSI device for scsi0:0, '/vmfs/volumes/<randomUUID><VMname>.vmdk'
  • Failed to attach filter 'hyper_cache' to scsi0:0: Not Found (195887107)

I am attempting to create a VM on the other side and migrate it into the Flash and then out of see if the same symptoms exist.

I will keep you posted.

I fixed this with a simple removal of these two fields in the advanced configuration of the VM.

If you are not aware on how to get to this, you select the  
VM --> Edit Settings --> Options Tab --> General --> click the "Configuration Parameters..."
if it is grayed out it is because your VM is powered on.

Scroll down until you find the two options listed and delete the contents of both fields.

Hit "Ok" and power up.

Till next time