[Libguestfs] [PATCH] builder: templates: For RHEL, CentOS >= 7 and all Fedora, default to GPT.

[Richard W.M. Jones]

On Tue, Oct 17, 2017 at 04:35:51PM +0100, Richard W.M. Jones wrote:
> The immediate issue is with Fedora/ppc64 and /ppc64le which currently
> use extended partitions, breaking the virt-builder ‘--size’ parameter,
> eg:
> 
>   $ virt-builder --arch ppc64le fedora-26 --size 20G
>   ...
>   [  21.6] Resizing (using virt-resize) to expand the disk to 20.0G
>   virt-resize: error: /dev/sda5: partition not found in the source disk image
>   (this error came from '--expand' option on the command line).  Try running
>   this command: virt-filesystems --partitions --long -a /var/tmp/vbf67b8c.img

Before this change, the fedora-26-ppc64 template looks like:

  Name       Type        VFS      Label  MBR  Size  Parent
  /dev/sda1  filesystem  unknown  -      -    4.0M  -
  /dev/sda2  filesystem  ext4     -      -    1.0G  -
  /dev/sda3  filesystem  swap     -      -    615M  -
  /dev/sda4  filesystem  unknown  -      -    1.0K  -
  /dev/sda5  filesystem  xfs      -      -    4.4G  -
  /dev/sda1  partition   -        -      41   4.0M  /dev/sda
  /dev/sda2  partition   -        -      83   1.0G  /dev/sda
  /dev/sda3  partition   -        -      82   615M  /dev/sda
  /dev/sda4  partition   -        -      05   1.0K  /dev/sda
  /dev/sda5  partition   -        -      83   4.4G  /dev/sda
  /dev/sda   device      -        -      -    6.0G  -

Note it's using MBR with an extended partition.

After this change:

  Name       Type        VFS      Label  MBR  Size  Parent
  /dev/sda1  filesystem  unknown  -      -    4.0M  -
  /dev/sda2  filesystem  ext4     -      -    1.0G  -
  /dev/sda3  filesystem  swap     -      -    615M  -
  /dev/sda4  filesystem  xfs      -      -    4.4G  -
  /dev/sda1  partition   -        -      -    4.0M  /dev/sda
  /dev/sda2  partition   -        -      -    1.0G  /dev/sda
  /dev/sda3  partition   -        -      -    615M  /dev/sda
  /dev/sda4  partition   -        -      -    4.4G  /dev/sda
  /dev/sda   device      -        -      -    6.0G  -

I didn't test virt-builder "full stack" yet, but virt-resize has no
problem, so this does appear to fix the original bug:

  $ virt-resize fedora-26-ppc64 output --expand /dev/sda4
  $ virt-filesystems -a output --all --long -h
  Name       Type        VFS      Label  MBR  Size  Parent
  /dev/sda1  filesystem  unknown  -      -    4.0M  -
  /dev/sda2  filesystem  ext4     -      -    1.0G  -
  /dev/sda3  filesystem  swap     -      -    615M  -
  /dev/sda4  filesystem  xfs      -      -    8.4G  -
  /dev/sda1  partition   -        -      -    4.0M  /dev/sda
  /dev/sda2  partition   -        -      -    1.0G  /dev/sda
  /dev/sda3  partition   -        -      -    615M  /dev/sda
  /dev/sda4  partition   -        -      -    8.4G  /dev/sda
  /dev/sda   device      -        -      -    10G   -

The VM also boots OK.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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