ubuntu@ubuntu:~$ gdisk
GPT fdisk (gdisk) version 0.6.14

Type device filename, or press <Enter> to exit: /dev/sdg
Problem opening /dev/sdg for reading! Error is 13.
You must run this program as root or use sudo!
ubuntu@ubuntu:~$ sudo gdisk
GPT fdisk (gdisk) version 0.6.14

Type device filename, or press <Enter> to exit: /dev/sdg
Problem reading disk in MBRData::ReadMBRData()!
Warning! Read error 22; strange behavior now likely!
Warning! Read error 22; strange behavior now likely!
Partition table scan:
  MBR: not present
  BSD: not present
  APM: not present
  GPT: not present

Creating new GPT entries.

Command (? for help):