Add functionality to add disk devices without formatting them

[afbjorklund]

Description

Make it an option to create disks, without adding the GPT partitions or the ext4 filesystem.

This probably means that the structure needs to become a map, but it could support both ?

additionalDisks:
- "data"

additionalDisks:
- name: "data"
  format: false

I was using it to try out Ceph, but I suppose there could be other uses for not formatting...

---

The workaround was to remove the filesystem (with wipefs) and remove the signature (with gdisk)

Then I was able to use cephadm, to start up the cluster using containers... Worked nicely, with dashboard.

[afbjorklund]

Changing file system would also be useful, for Gluster:

mkfs.xfs -i size=512

The default value of the such an "mkfs" parameter is:

mkfs.ext4

[afbjorklund]

Once cephadm is done with it, it's actually using LVM.

root@lima-ceph:/# pvs
  PV         VG                                        Fmt  Attr PSize   PFree
  /dev/vdb   ceph-77b946de-840e-4b15-b127-35b290c4f81a lvm2 a--  <50.00g    0 
root@lima-ceph:/# lvs
  LV                                             VG                                        Attr       LSize   Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  osd-block-f487ff0e-51c4-4dc9-878f-d565e2929867 ceph-77b946de-840e-4b15-b127-35b290c4f81a -wi-a----- <50.00g                                                    

So it should probably skip trying to repartion it later...

[   15.162669] cloud-init[4393]: + [[ ! -b /dev/disk/by-label/lima-data ]]
[   15.163329] cloud-init[4393]: + echo type=linux
[   15.166989] cloud-init[4393]: + sfdisk --label gpt /dev/vdb
[   15.169010] cloud-init[4393]: Checking that no-one is using this disk right now ... FAILED
[   15.169777] cloud-init[4393]: This disk is currently in use - repartitioning is probably a bad idea.
[   15.170512] cloud-init[4393]: Umount all file systems, and swapoff all swap partitions on this disk.
[   15.171286] cloud-init[4393]: Use the --no-reread flag to suppress this check.
[   15.172393] cloud-init[4393]: sfdisk: Use the --force flag to overrule all checks.