Comment 11 for bug 1746073

Tim,

I confirm that both constraints (root-disk-source and root-disk) are indeed working as expected.

ubuntu@niedbalski-bastion:~/juju_config/2.x$ sudo snap refresh juju --candidate --classic
snap "juju" has no updates available
ubuntu@niedbalski-bastion:~/juju_config/2.x$ juju --version
2.6.4-bionic-amd64
ubuntu@niedbalski-bastion:~/juju_config/2.x$ juju add-machine --constraints "root-disk-source=volume root-disk=67G"
created machine 1
ubuntu@niedbalski-bastion:~/juju_config/2.x$ juju machines |grep -E ^1
1 pending pending bionic instance "512668c2-c6ca-4c10-b418-99576d7e7256" has status BUILD, wait 10 seconds before retry, attempt 1
ubuntu@niedbalski-bastion:~/juju_config/2.x$ openstack server show 512668c2-c6ca-4c10-b418-99576d7e7256|grep volumes

| volumes_attached | id='edd6502f-fedd-4781-a2ed-8d41ed9fd6c0'

ubuntu@niedbalski-bastion:~/juju_config/2.x$ openstack volume show edd6502f-fedd-4781-a2ed-8d41ed9fd6c0 -c size |grep 67
| size | 67 |

root@juju-e3eeba-default-1:/home/ubuntu# df -kh|grep -i vda
/dev/vda1 65G 1.4G 64G 3% /
/dev/vda15 105M 3.6M 101M 4% /boot/efi

Thanks for the fix!.