Offline VM Migration auto convert RDM to VMDK format

Due to some reconfiguration work we performed on our Virtual Infrastructure, we had required to relocate some of the VM to a different datastore. These VMs which required to be moved had been attached with Raw Device Mapping (RDM). Previously I thought the offline storage migration will not move the RDM over to the datastore as RDM is referring to the raw device from the SAN storage.Actually I was planned to convert the RDM to VMDK which I planned to manual transfer the files I need from RDM to the new virtual disk I created.

In a test yesterday, we found that a offline VM migration will auto convert the RDM which attach to the virtual machine to the VMDK format when I selected the data store to be moved in offline mode. This was really surprise myself and simplify my work actually, as I do not require some manual file transfer from the RDM to the new virtual disk.

ESX and VM Guest - Round Robin Storage Setting

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 To improve the I/O performance for ESX Virtual Infrastructure, VMware had come out with the round robin option for both ESX and VM guests. Although is an experimental option in the ESX setting today, but I will encourage you all to try this option which provide fail over and load balancing on the storage path to connect to you SAN storage. For VM guests, you will allow to use this when you have RDM - Raw Device Mapping option to direct read write to the physical LUN from your SAN storage without using VMFS.
ESX Hosts

To enable this on ESX host, you need to browse to the configuration tab of the ESX host, and right click the data store and select properties, and click on manage paths option in the GUI wizard. Click on Change button after that, and choose the Round Robin (Experimental) option and click OK. You will need to go through this process 1 by 1 to ensure you had round robin from each ESX host to each of the VMFS Data store.

VM Guests

Just right click the VM

and choose edit setting, and select to the hard disk which has shown as Mapped Raw LUN on the summary tab. Click on the Manage Paths and follow by the change button, and same you can easily

configure to have the Round Robin enable.