Turns out it's cloud-config.service (not cloud-init.service) that does the mkfs:
paulmey@testvm3:~$ journalctl -b -ojson|jq 'select(.MESSAGE|contains("mkfs"))|._SYSTEMD_UNIT' "cloud-config.service" "cloud-config.service" "cloud-config.service" "cloud-config.service" "cloud-config.service" I changed that in /usr/lib/python3/dist- packages/cloudinit/config/cc_mounts.py and rebooted twice, once to write the new fstab, then the second reboot actually reformats: paulmey@testvm3:~$ mount|grep sdb ; grep mnt /etc/fstab /dev/sdb1 on /mnt type ext4 (rw,relatime,data=ordered) /dev/disk/cloud/azure_resource-part1 /mnt auto defaults,nofail,x-systemd.requires=cloud-config.service,comment=cloudconfig 0 2 I think the only thing that needs to change is to require cloud- config.service instead of cloud-init.service ? -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1611074 Title: Reformatting of ephemeral drive fails on resize of Azure VM To manage notifications about this bug go to: https://bugs.launchpad.net/cloud-init/+bug/1611074/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs