It might be useful to re-scan the SCSI bus when a new device has been plugged in, e.g. via VMWare ESXi configuration changes, that has not been automatically identified by the OS. In Debian/Ubuntu you can do the following:
sudo apt-get install scsitools
sudo rescan-scsi-bus.sh
You can check the /sys/bus/scsi/devices/ directory before and after the re-scan and via dmesg to which device node in /dev directory e.g. the new harddisk has been added.
The internet representation of Andreas Arens