Access a Physical Drive in a Ubuntu VM on ESX 4

Question

I am in the process of playing around with ESX and one of the projects I took on is converting my old NAS to a VM. This was pretty straight forward but now I have some problem with storage.

The NAS had 3 drives, one was OS/Apps only and the rest was Data. Now I need the VM to connect to the 2 drives directly and cant seem to see how to do this in ESX4. When I go to "Add Hardware" and select SCSI Drive I only see my CD Rom Drive. The ESX installation itself see the added drive, but it seems I cant get the VM (Ubuntu) to access it. Can ESX be setup to allow VM access to physical hard drive, and if so how.

Thanks

Answer 1

If your physical storage hardware is suitable (iSCSI or Fibre Channel SAN LUNs) then you can create a Raw Device Mapping that allows you to add a physical drive (or a partition) directly to the VM - Chapter 10 of the ESX Configuration Guide has some more details on how to work with RDM's. The critical point to note for RDM's is that they are intended for SAN attached storage not local disks and they are the only supported way to map physical volumes as VM drives with vSphere.

It may be possible to add a drive as a generic SCSI device if you have the right drive\controller hardware and aren't too worried about VMware support. There's a discussion on the process in this VMware Communities discussion that used to work with earlier ESX versions. It has gotten more difficult in recent (v3.5 and v4) ESX\ESXi versions and requires a significant amount of VMX file hacking in order to fool ESX into accepting the mapping. This article by Edward Haletky on ITKE outlines a procedure that can work ESX 3.5.