fdisk reads the list in /proc/partitions. If the disk doesn't show up there it won't be used. You can also check to see if there is a device in /dev/sd? that isn't already in use (if you only have one, it should be /dev/sda, a new one would be /dev/sdb. If /dev/sdb exists there but not in /proc/partitions, then try using partprobe to read any existing tables.
To get the partitions there requires the bus to be scanned (or the system rebooted). Partitions may be searched for using the partprobe, but I'm not sure it initiates a rescan of the SCSI bus for new devices (which is why rebooting is simpler).
Try using "partprobe" (no parameters - if the device exists in /dev, you can use partprobe /dev/sd? to load just that disk) to see if it adds the device.
Last edited by jpollard; 05-13-2015 at 07:28 AM.