Partitioning drive with existing partition fails

[Patrick G]

Attempting to partition a device in AWS using mbr fails when there is an existing filesystem detected. Per smoser this is due to the need to wipefs which cloud-init doesn't currently do.

Cloud-init config:

#cloud-config
disk_setup:
    ephemeral1:
        table_type: mbr
        layout: true
        overwrite: true

fs_setup:
  - label: None
    filesystem: ext4
    device: ephemeral1
    partition: auto
    overwrite: true

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: cloud-init 17.1-27-geb292c18-0ubuntu1~16.04.1
ProcVersionSignature: Ubuntu 4.4.0-1041.50-aws 4.4.95
Uname: Linux 4.4.0-1041-aws x86_64
ApportVersion: 2.20.1-0ubuntu2.13
Architecture: amd64
CloudName: Amazon - Ec2
Date: Mon Dec 4 18:29:50 2017
Ec2AMI: ami-ed019997
Ec2AMIManifest: qbis-amis/image-1512159879.manifest.xml
Ec2AvailabilityZone: us-east-1b
Ec2InstanceType: c3.2xlarge
Ec2Kernel: unavailable
Ec2Ramdisk: unavailable
PackageArchitecture: all
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: cloud-init
UpgradeStatus: No upgrade log present (probably fresh install)

[Scott Moser (smoser)]

As suggested to Patrick in IRC, this can be worked around by partitioning with gpt rather than MBR.