root@host:/# gdisk /dev/sda
GPT fdisk (gdisk) version 0.8.1

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

Found valid GPT with protective MBR; using GPT.

Command (? for help): p
Disk /dev/sda: 1171743836 sectors, 558.7 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): 1C75FB7D-29C1-46AF-8547-7D6857B22DB9
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 585871930
Partitions will be aligned on 1024-sector boundaries
Total free space is 1561 sectors (780.5 KiB)

Number  Start (sector)    End (sector)  Size       Code  Name
   1            1024          409599   199.5 MiB   0700
   2          409600       585871359   279.2 GiB   8E00

Command (? for help): d
Partition number (1-2): 2

Command (? for help): n
Partition number (2-128, default 2): 2
First sector (34-585871930, default = 409600) or {+-}size{KMGTP}:
Last sector (409600-585871930, default = 585871930) or {+-}size{KMGTP}: +500G
Last sector (409600-585871930, default = 585871930) or {+-}size{KMGTP}:
Current type is 'Linux filesystem'
Hex code or GUID (L to show codes, Enter = 8300):
Changed type of partition to 'Linux filesystem'

Command (? for help): p
Disk /dev/sda: 1171743836 sectors, 558.7 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): 1C75FB7D-29C1-46AF-8547-7D6857B22DB9
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 585871930
Partitions will be aligned on 1024-sector boundaries
Total free space is 990 sectors (495.0 KiB)

Number  Start (sector)    End (sector)  Size       Code  Name
   1            1024          409599   199.5 MiB   0700
   2          409600       585871930   279.2 GiB   8300  Linux filesystem

Command (? for help): n
Partition number (3-128, default 3):
First sector (34-1023, default = 34) or {+-}size{KMGTP}: 585871931
First sector (34-1023, default = 34) or {+-}size{KMGTP}: