Hello MrRedPants, Since you are using non-redundant setup you will have issues trying to change paths between controllers since both hosts only have a single connection to the MD3000.  What you could do if available is to get 2 more SAS cables & cable the second ports on the MD to the opposite raid controller than the host is connected to currently.   Now if that is not an option then what you can do is to have 2 disk groups and assign the virtual disks/ Luns that are connected to each host into their own disk group.  If you are going to make each host their own disks groups then you will need to stop the I/O while you are moving the virtual disk to the new disk group so that you want have any data loss.   Please let us know if you have any other questions.
Current setup Powervault MD3000 (Removed by moderator) - attached to two PowerEdge R610 servers using Dell SAS 5/e Adapter card in each r610. The R610s are each acting as an ESX host running VMWare ESXi 5.5.0 We created multiple LUNs on the storage array and noticed that all traffice was going through one RAID controller module or the other (and it would appear to change without prompting when looking at storage array). I powered down a two different virtual machines to try to change the path and got an error after some delay - I've pasted this error below. I also tried to redistribute the virual disks under the support tab of the MDSM software to no avail. In doing some reading, it would appear that the LUNs should have been allocated to a particular raid controller before any I/0, but, I still feel like we are missing something as to why we cannot distribute traffic appropriately.  According to some documentation for a MD3200 -  OPERATING ENVIRONMENT DATA Client system name: FLMGMT01Client OS: Windows Server 2008 R2 Application version: 03.35.G6.88Storage array management version: 03.35.G6.88Storage array name: VAB-NAS-01Firmware version: 07.35.39.64Management class: devmgr.v1035api01.Manager ************************************************** ERROR DATA Command sent to RAID controller module in slot: 0Host name: 192.168.19.233IP address: 192.168.19.233 Return code: Error 29 - This operation cannot complete because there was a security authentication failure on a parameter in the command sent to the RAID controller module. Please retry the operation. If this message persists, contact your Technical Support Representative.Operation when error occurred: PROC_assignVolumeOwnershipTimestamp: Aug 25, 2014 4:18:59 PM STACK DATA devmgr.v1035api01.sam.jal.ManagementOperationFailedException: at devmgr.v1035api01.sam.jal.SYMbolClient.dispatchOperation(Unknown Source)at devmgr.v1035api01.sam.jal.StorageArrayFacade.issueCommand(Unknown Source)at devmgr.v1035api01.sam.jal.StorageArrayFacade.sendCommandCommon(Unknown Source)at devmgr.v1035api01.sam.jal.StorageArrayFacade.sendCommand(Unknown Source)at devmgr.v1035api01.sam.jal.StorageArrayFacade.assignVolumeOwnership(Unknown Source)at devmgr.v1035api01.sam.configuration.controller.ChangeControllerOwnershipDialogPanel.performCommitAction(Unknown Source)at devmgr.v1035api01.shared.wizard.DialogPanel$NotifyBackgroundTaskAdapter.performOp(Unknown Source)at devmgr.v1035api01.shared.AbstractTaskAdapter.run(Unknown Source) THREAD DATA Thread[Reference Handler,10,system]Thread[Finalizer,8,system]Thread[Signal Dispatcher,9,system]Thread[Attach Listener,5,system]Thread[Java2D Disposer,10,system]Thread[TimerQueue,5,system]Thread[Swing-Shell,6,system]Thread[AWT-Shutdown,5,main]Thread[AWT-Windows,6,main]Thread[EventQueueMonitor-ComponentEvtDispatch,5,main]Thread[Thread-3,5,main]Thread[AWT-EventQueue-0,6,main]Thread[DestroyJavaVM,5,main]Thread[SwingWorker-pool-2-thread-1,5,main]Thread[ChangeDetector,6,main]Thread[PreferenceStoreChangeDetector,6,main]Thread[LogMsgThread,6,main]Thread[Np_Link_Monitor0,6,main]Thread[DMVGarbageCollectorThread,6,main]Thread[RecoveryProfile-27,6,main]Thread[AEN-28,6,main]Thread[RecoveryProfile-30,6,main]Thread[AEN-31,6,main]Thread[Timer-0,6,main]Thread[RecoveryProfile-35,6,main]Thread[AEN-36,6,main]Thread[RecoveryProfile-38,6,main]Thread[AEN-39,6,main]Thread[Timer-1,6,main]Thread[Timer-2,6,main]Thread[Timer-3,6,main]Thread[RecoveryProfile-48,6,main]Thread[AEN-49,6,main]Thread[Timer-4,6,main]Thread[RecoveryProfile-53,6,main]Thread[AEN-54,6,main]Thread[Timer-5,6,main]Thread[SwingWorker-pool-2-thread-2,5,main]Thread[RecoveryProfile-69,6,main]Thread[AEN-70,6,main]Thread[Timer-14,6,main]Thread[Timer-91,6,main]Thread[Image Animator 2,3,main]  
MD3000 cannot change virtual disk ownership / preffered path - ERROR 29