Firstly, install scsitools package:

sudo apt install scsitools

Then run the command rescan-scsi-bus:

sudo rescan-scsi-bus

That’s it, your new virtual HDD has now been detected.

Another way would be to do it with a loop and without the need for that package:

for host in ls /sys/class/scsi_host/; do
echo "- - -" > /sys/class/scsi_host/${host}/scan;
done

Enjoy!

Sources:

• http://manpages.ubuntu.com/manpages/trusty/man8/rescan-scsi-bus.8.html
• My colleague Anastasios Fragopoulos