gdisk

ubuntu@ubuntu:~$ sudo gdisk /dev/sda
GPT fdisk (gdisk) version 0.8.8

Warning! Disk size is smaller than the main header indicates! Loading
secondary header from the last sector of the disk! You should use 'v' to
verify disk integrity, and perhaps options on the experts' menu to repair
the disk.
Caution: invalid backup GPT header, but valid main header; regenerating
backup header from main header.

Warning! One or more CRCs don't match. You should repair the disk!

Partition table scan:
  MBR: protective
  BSD: not present
  APM: not present
  GPT: damaged

****************************************************************************
Caution: Found protective or hybrid MBR and corrupt GPT. Using GPT, but disk
verification and recovery are STRONGLY recommended.
****************************************************************************

Command (? for help): v

Caution: The CRC for the backup partition table is invalid. This table may
be corrupt. This program will automatically create a new backup partition
table when you save your partitions.

Problem: The secondary header's self-pointer indicates that it doesn't reside
at the end of the disk. If you've added a disk to a RAID array, use the 'e'
option on the experts' menu to adjust the secondary header's and partition
table's locations.

Problem: Disk is too small to hold all the data!
(Disk size is 250069680 sectors, needs to be 500129792 sectors.)
The 'e' option on the experts' menu may fix this problem.

Problem: GPT claims the disk is larger than it is! (Claimed last usable
sector is 500129758, but backup header is at
500129791 and disk size is 250069680 sectors.
The 'e' option on the experts' menu will probably fix this problem

Problem: partition 4 is too big for the disk.

Identified 5 problems!