With virtualization, we have opened up some possibilities that was not possible on some servers, one of those possibilities is to add a hard disk on the fly to any server. This is especially great when you need to add more storage to a file server / backup / etc..
Now don't get me wrong, I know we could have done this before. But there was a cost barrier to that kind of solution with specific hardware, virtualization enables this on all VMs.
In windows, when adding a new virtual hard drive, the system will just detect the change and publish it in my computer (although sometimes a rescan in the server manager is required). In linux, its not that straight forward when we are dealing with a GUI-less server.
Thankfully there is a command that will rescan the SCSI bus and detect new hard drives:
echo "- - -" > /sys/class/scsi_host/host0/scan
this will detect new hard drives and display them in /dev
After that, mount the new drives to whatever mount point you choose.