When you hotplug a hard drive in a virtual machine, the drive do not show in
fdisk -l output until you reboot your VM.
In order to get the drive to appear, the SCSI bus need to be rescanned.
The rescan will be triggered through
sysfs pseudo filesystem.
First of all get root access and check what host is available:
# ls /sys/class/scsi_host host0 host1 host2 host3
Pick up the one (here host2 is taken) that match where the drive is and run:
# echo "- - -" > /sys/class/scsi_host/host2/scan
That is 3 “-“ separated by a space
Now, you should be able to see the drive when running:
# fdisk -l