Sometimes, you need your VMs to access a LUN directly over iSCSI. Direct access comes in handy when you, let’s say, run SAN/NAS-aware applications on vSphere VMs, or if you’re going to deploy some hardware-specific SCSI commands. Also, with direct access, physical-to-virtual conversion becomes possible without migrating a massive LUN to VMDK. Whatever. To enable your VMs to talk directly to LUN, you need a raw device mapping file. Recently, I created vSphere VMs with such disks. Well, apparently, this case is not unique, so I decided to share my experience in today’s article.