zpool: state=present is not idempotent

[SudoNova]

Summary

First time that I try creating a pool It's ok but the second time I get this error:

[WARNING]: zpool add only supports 'ashift', ignoring: ['autotrim']
fatal: [synapse]: FAILED! => {"changed": false, "cmd": "/usr/sbin/zpool add tkh sdb", "msg": "/dev/sdb is in use and contains a unknown filesystem.", "rc": 1, "stderr": "/dev/sdb is in use and contains a unknown filesystem.\n", "stderr_lines": ["/dev/sdb is in use and contains a unknown filesystem."], "stdout": "", "stdout_lines": []}

Issue Type

Bug Report

Component Name

zpool

Ansible Version

ansible [core 2.18.7]
  config file = /home/alvin/git/ansible/ansible.cfg
  configured module search path = ['/home/alvin/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /nix/store/09n1iiq52wcy508ivv37hbh9d00fgvz0-python3.12-ansible-core-2.18.7/lib/python3.12/site-packages/ansible
  ansible collection location = /home/alvin/.ansible/collections:/usr/share/ansible/collections
  executable location = /nix/store/09n1iiq52wcy508ivv37hbh9d00fgvz0-python3.12-ansible-core-2.18.7/bin/ansible
  python version = 3.12.11 (main, Jun  3 2025, 15:41:47) [GCC 14.3.0] (/nix/store/bbyp6vkdszn6a14gqnfx8l5j3mhfcnfs-python3-3.12.11/bin/python3.12)
  jinja version = 3.1.6
  libyaml = True

Community.general Version

11.2.1

Configuration

OS / Environment

NixOs 25.05

Steps to Reproduce

- name: Configure Zpool
  become: true
  community.general.zpool:
    name: tkh
    pool_properties:
      autotrim: on
    filesystem_properties:
      atime: off
      compression: zstd
      mountpoint: legacy
      recordsize: 1M
      xattr: sa
    vdevs:
      - disks: "{{ fs.zfs.devs | default(['sdb']) }}"
    state: present
  when:
    - fs is defined
    - fs.zfs is defined

Expected Results

Ok

Actual Results

Code of Conduct

• I agree to follow the Ansible Code of Conduct

[ansibullbot]

Files identified in the description:

• plugins/modules/beadm.py

If these files are incorrect, please update the component name section of the description or use the !component bot command.

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[ansibullbot]

cc @bcoca @fishman @jasperla @jpdasma @mator @scathatheworm @troy2914 @xen0l
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[felixfontein]

!component =plugins/modules/zpool.py

[ansibullbot]

Files identified in the description:

• plugins/modules/zpool.py

If these files are incorrect, please update the component name section of the description or use the !component bot command.

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[ansibullbot]

cc @tomhesse
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[dthomson-triumf]

If I can add to this, I'm coming up against the same error message.

The problem for me is that I'm specifying the vdev disks with a symlink (/dev/disk/by-id/ata-...) but the zpool module gets disks with the full real path of these devices, so it ends up with /dev/sd? compared to my /dev/disk/..., then thinks my zpools are different when they're not.

A possible fix could be to follow the symlinks for provided vdev disks, or to allow the zpool module to use the non-real disk representations, maybe through an additional flag or something?

[dthomson-triumf]

If I can add to this, I'm coming up against the same error message.

The problem for me is that I'm specifying the vdev disks with a symlink (/dev/disk/by-id/ata-...) but the zpool module gets disks with the full real path of these devices, so it ends up with /dev/sd? compared to my /dev/disk/..., then thinks my zpools are different when they're not.

A possible fix could be to follow the symlinks for provided vdev disks, or to allow the zpool module to use the non-real disk representations, maybe through an additional flag or something?

Oh I see that #10744 already noted this.

[vbotka]

The module can't create a correct diff. For example,

(Pdb) p vdev_layout_diff
{'before': {'vdevs': [{'type': 'stripe', 'disks': ['/dev/ada2']}, {'type': 'stripe', 'disks': ['/dev/ada3']}]},
 'after': {'vdevs': [{'type': 'stripe', 'disks': ['/dev/ada2', '/dev/ada3']}]}}

This makes the module not idempotent.

    - community.general.zpool:
        name: iocage
        vdevs: "{{ vdevs }}"
      vars:
        vdevs:
          - disks: [/dev/ada2, /dev/ada3]

It crashes when running repeatedly. For example,

[ERROR]: Task failed: Module failed: invalid vdev specification
use '-f' to override the following errors:
/dev/ada2 is part of active pool 'iocage'
/dev/ada3 is part of active pool 'iocage'
Origin: /export/scratch/sandbox/tmp1/test-190/pb6.yml:8:7

6   tasks:
7
8     - community.general.zpool:
        ^ column 7

fatal: [planx]: FAILED! => 
    changed: false
    cmd: /sbin/zpool add -n iocage /dev/ada2 /dev/ada3
    msg: |-
        invalid vdev specification
        use '-f' to override the following errors:
        /dev/ada2 is part of active pool 'iocage'
        /dev/ada3 is part of active pool 'iocage'
    rc: 1
    stderr: |-
        invalid vdev specification
        use '-f' to override the following errors:
        /dev/ada2 is part of active pool 'iocage'
        /dev/ada3 is part of active pool 'iocage'
    stderr_lines: <omitted>
    stdout: ''
    stdout_lines: <omitted>

The -f suggestion is terrifying.

[yacoob]

An extra note: encryption is another property that is read only and can only be set during zfs dataset creation. So if you create a pool where all child datasets should be encrypted and use zpool create -O encryption=on ... via filesystem_properties of community.general.zpool, it'll get created properly, only to fail on the second run.

[SandiyosDev]

anyone interested in making a pr?