azure - Ansible parted command fails when new disk "being used"

Question

Using Ansible v2.10.4 to configure RHEL 8 VMs on Azure IaaS, and am trying to use the parted directive to partition a new data disk:

- name: Partition the data disk for app use.
  parted:
    device: /dev/sdc
    number: 1
    state: present
    align: optimal
    label: msdos
    part_start: 0%
    part_end: 100%
    part_type: primary

This generally works about half the time; when it doesn't, it fails with this message:

FAILED! => {"changed": false, "err": "Error: Partition(s) on /dev/sdc are being used.
", "msg": "Error while running parted script: /sbin/parted -s -m -a optimal /dev/sdc -- unit KiB mklabel msdos mkpart primary 0% 100%", "out": "", "rc": 1}

While I'm not sure why a newly created, unpartitioned/unformatted disk would be "in use", I added this directive above it to remove any partitions:

- name: First ensure the data disk is "de-partitioned" (so next call to parted doesn't fail).
  parted:
    device: /dev/sdc
    number: 1
    state: absent

Sometimes this works, but other times, it also fails with a slightly different (but effectively the same) message:

FAILED! => {"changed": false, "err": "Warning: Partition /dev/sdc1 is being used. Are you sure you want to continue?
", "msg": "Error while running parted script: /sbin/parted -s -m -a optimal /dev/sdc -- rm 1", "out": "", "rc": 1}

Is there any way with Ansible to test whether a disk is "in use" before attempting to do anything with it?

question from:https://stackoverflow.com/questions/65850971/ansible-parted-command-fails-when-new-disk-being-used

Answer 1

Found out that when the RHEL system boots, there's no guarantee that the second disk will be the /dev/sdc device; uncovered that when it fails, it was allocated as /dev/sdb). So having to work through determining the device name at the time I need to access it.