1. Introduction

1.1. What this package provides

The zhmcclient package (also known as python-zhmcclient) is a client library written in pure Python that interacts with the Web Services API of the Hardware Management Console (HMC) of IBM Z or LinuxONE machines. The goal of this package is to make the HMC Web Services API easily consumable for Python programmers.

The HMC Web Services API is the access point for any external tools to manage the IBM Z or LinuxONE platform. It supports management of the lifecycle and configuration of various platform resources, such as partitions, CPU, memory, virtual switches, I/O adapters, and more.

The zhmcclient package encapsulates both protocols supported by the HMC Web Services API:

  • REST over HTTPS for request/response-style operations driven by the client. Most of these operations complete synchronously, but some long-running tasks complete asynchronously.

  • JMS (Java Messaging Services) for notifications from the HMC to the client. This is used for notification about changes in the system, or about completion of asynchronous tasks started using REST.

1.1.1. zhmc CLI

Before version 0.18.0 of the zhmcclient package, it contained the zhmc CLI. Starting with zhmcclient version 0.18.0, the zhmc CLI has been moved from this project into the new zhmccli project.

If your project uses the zhmc CLI, and you are upgrading the zhmcclient package from before 0.18.0 to 0.18.0 or later, your project will need to add the zhmccli package to its dependencies.

1.2. Supported environments

The zhmcclient package is supported in these environments:

  • Operating systems: Linux, Windows (native, and with UNIX-like environments), OS-X

  • Python versions: 2.7, 3.5, and higher 3.x

  • HMC versions: 2.11.1 and higher

The following table shows for each HMC version the supported HMC API version and the supported IBM Z machine generations. The corresponding LinuxONE machine generations are listed in the notes below the table:

HMC version

HMC API version

HMC API book

Machine generations


1.1 - 1.2

HMC API 2.11.1

z196 and z114



HMC API 2.12.0

z196 to zEC12 and z114


1.4 - 1.5

HMC API 2.12.1

z196 to zEC12 and z114 to zBC12



HMC API 2.13.0

z196 to z13 (1) and z114 to zBC12


1.7, 2.1 - 2.2

HMC API 2.13.1

z196 to z13 (1) and z114 to z13s (2)


2.20 - 2.25

HMC API 2.14.0

z196 to z14 (3) and z114 to z13s (2)


2.35 - 2.40

HMC API 2.14.1

z196 to z14 (3) and z114 to z14-ZR1 (4)


3.1 - 3.4

HMC API 2.15.0

z196 to z15 (5) and z114 to z14-ZR1 (4)


  1. Supported for z13 and LinuxONE Emperor

  2. Supported for z13s and LinuxONE Rockhopper

  3. Supported for z14 and LinuxONE Emperor II

  4. Supported for z14-ZR1 and LinuxONE Rockhopper II

  5. Supported for z15 and LinuxONE III

1.3. Installation

The easiest way to install the zhmcclient package is by using Pip. Pip ensures that any dependent Python packages also get installed.

With Pip, there are three options for where to install a Python package and its dependent packages:

  • Into a virtual Python environment. This is done by having the virtual Python environment active, and running the Pip install commands as shown in the following sections.

    This option is recommended if you intend to develop programs using the zhmcclient API, because the packages you install do not interfere with other Python projects you may have.

  • Into the system Python, just for the current user. This is done by not having a virtual Python environment active, and by using the --user option on the Pip install commands shown in the following sections.

    This option is recommended if you intend to only use the zhmc CLI, or if you are not concerned about interfering with other Python projects you may have.

  • Into the system Python, for all users of the system. This is done by not having a virtual Python environment active, and by using sudo on the Pip install commands shown in the following sections.

    Be aware that this option will replace the content of existing Python packages, e.g. when a package version is updated. Such updated packages as well as any newly installed Python packages are not known by your operating system installer, so the knowledge of your operating system installer is now out of sync with the actual set of packages in the system Python.

    Therefore, this approach is not recommended and you should apply this approach only after you have thought about how you would maintain these Python packages in the future.

1.3.1. Installation of latest released version

The following command installs the latest released version of the zhmcclient package from Pypi into the currently active Python environment:

$ pip install zhmcclient

This installs everything you need to program against the client API.

The package provides an extra named ‘testutils’ that installs additional Python packages that are needed for using the ‘zhmcclient.testutils’ sub-package which provides support for end2end testing against a real HMC, and is also used in the example scripts. See zhmcclient.testutils module for details.

That extra is installed with:

$ pip install zhmcclient[testutils]

1.3.2. Installation of latest development version

If you want to install the latest development level of the zhmcclient package instead for some reason, you can install directly from the master branch of its Git repository:

$ pip install git+https://github.com/zhmcclient/python-zhmcclient.git@master#egg=zhmcclient

1.3.3. Installation on a system without Internet access

In both cases described above, Internet access is needed to access these repositories.

If you want to install the zhmcclient package on a system that does not have Internet access, you can do this by first downloading the zhmcclient package and its dependent packages on a download system that does have Internet access, transferring these packages to the target system, and installing them on the target system from the downloaded packages:

  1. On a system with Internet access, download the zhmcclient package and its dependent packages:

    [download-system]$ mkdir packages
    [download-system]$ cd packages
    [download-system]$ pip download zhmcclient
    Collecting zhmcclient
      Using cached https://files.pythonhosted.org/packages/c3/29/7f0acab22b27ff29453ac87c92a2cbec2b16014b0d32c36fcce1ca285be7/zhmcclient-0.19.0-py2.py3-none-any.whl
      Saved ./zhmcclient-0.19.0-py2.py3-none-any.whl
    Collecting stomp-py>=4.1.15 (from zhmcclient)
    . . .
    Successfully downloaded zhmcclient decorator pytz stomp-py six requests docopt urllib3 certifi chardet idna
    [download-system]$ ls -1
  2. Transfer all downloaded package files to the target system. Note that the package files are binary files.

    The actual files you see in your directory may not be the same ones shown in this section, because new package versions may have been released meanwhile, and new versions may even have different dependent packages.

  3. On the target system, install the zhmcclient package in a way that causes Pip not to go out to the Pypi repository on the Internet, and instead resolves its dependencies by using the packages you transferred from the download system into the current directory:

    [target-system]$ ls -1
    [target-system]$ pip install -f . --no-index --upgrade zhmcclient-*.whl
    Looking in links: .
    . . .
    Installing collected packages: decorator, pytz, docopt, stomp-py, six,
      urllib3, certifi, chardet, idna, requests, zhmcclient
    Successfully installed certifi-2019.11.28 chardet-3.0.4 decorator-4.4.1
      docopt-0.6.2 idna-2.8 pytz-2019.3 requests-2.22.0 six-1.13.0
      stomp-py-4.1.22 urllib3-1.25.7 zhmcclient-0.25.1

1.3.4. Alternative installation methods and sources

The installation using Pip as shown in the previous sections uses the wheel distribution archive from Pypi. This is the fastest installation method and source and does not normally need to be changed.

In case you have a need to install from alternative sources, or cannot use Pip for some reason, here are some alternative installation methods and sources:

  • Pip install from wheel distribution archive (the normal case discussed earlier):

    $ pip install zhmcclient
  • Pip install from source distribution archive:

    # Download the source dist archive (you can also use any other means to get it):
    $ pip download zhmcclient --no-binary zhmcclient
    # Install from the source dist archive:
    $ pip install zhmcclient-0.26.1.tar.gz  # adjust version
  • Pip install from repo root directory:

    $ git clone https://github.com/zhmcclient/python-zhmcclient
    $ cd python-zhmcclient
    $ pip install .

Note that an installation of Python packages using setup.py install is no longer recommended by the Python packaging community. For details, see https://blog.ganssle.io/articles/2021/10/setup-py-deprecated.html. Installation with setup.py install is no longer supported by this package.

1.3.5. Verification of the installation

You can verify that the zhmcclient package and its dependent packages are installed correctly by importing the package into Python:

$ python -c "import zhmcclient; print('ok')"

1.3.6. Considerations for Windows

On Windows, you can run your Python scripts on native Windows or in a UNIX-like environment (such as CygWin, MSYS2, Babun, or Gow).

Running Python scripts on native Windows means they run in the Windows command processor, and use a Python installed on Windows.

Running Python scripts in a UNIX-like environment means they run in the shell of the UNIX-like environment, and use the Python of the UNIX-like environment.

The zhmcclient package can be used in any of these scenarios. It is tested on the Appveyor CI on native Windows, with CygWin and with MSYS2.

1.4. Setting up the HMC

Usage of the zhmcclient package requires that the HMC in question is prepared accordingly:

  1. The Web Services API must be enabled on the HMC.

    You can do that in the HMC GUI by selecting “HMC Management” in the left pane, then opening the “Configure API Settings” icon on the pain pane, then selecting the “Web Services” tab on the page that comes up, and finally enabling the Web Services API on that page.

    The above is on a z16 HMC, it may be different on older HMCs.

    If you cannot find this icon, then your userid does not have permission for the respective task on the HMC. In that case, there should be some other HMC admin you can go to to get the Web Services API enabled.

  2. To use all functionality provided in the zhmcclient package, the HMC user ID that will be used by the zhmcclient must be authorized for the following tasks. The description of each method of the zhmcclient package will mention its specific authorization requirements.

    • “Remote Restart” must be enabled on the HMC

    • Use of the Web Services API

    • Shutdown/Restart

    • Manage Alternate HMC

    • Audit and Log Management

    • View Security Logs

    • Manage LDAP Server Definitions

    • Manage Password Rules

    • Manage Users

    • Manage User Patterns

    • Manage User Roles

    • Manage User Templates

    When using CPCs in DPM mode:

    • Start (a CPC in DPM mode)

    • Stop (a CPC in DPM mode)

    • New Partition

    • Delete Partition

    • Partition Details

    • Start Partition

    • Stop Partition

    • Dump Partition

    • PSW Restart (a Partition)

    • Create HiperSockets Adapter

    • Delete HiperSockets Adapter

    • Adapter Details

    • Manage Adapters

    • Export WWPNs

    When using CPCs in classic mode (or ensemble mode):

    • Activate (an LPAR)

    • Deactivate (an LPAR)

    • Load (an LPAR)

    • Customize/Delete Activation Profiles

    • CIM Actions ExportSettingsData

  3. (Optional) If desired, the HMC user ID that will be used by the zhmcclient can be restricted to accessing only certain resources managed by the HMC. To establish such a restriction, create a custom HMC user role, limit resource access for that role accordingly, and associate the HMC user ID with that role.

    The zhmcclient needs object-access permission for the following resources:

    • CPCs to be accessed

    For CPCs in DPM mode:

    • Partitions to be accessed

    • Adapters to be accessed

    For CPCs in classic mode (or ensemble mode):

    • LPARs to be accessed

1.5. Setting up firewalls or proxies

If you have to configure firewalls or proxies between the client system and the HMC, the following ports need to be opened:

  • 6794 (TCP) - for the HMC API HTTP server

  • 61612 (TCP) - for the HMC API message broker via JMS over STOMP

For details, see sections “Connecting to the API HTTP server” and “Connecting to the API message broker” in the HMC API book.

1.6. Examples

The following example code lists the partitions on CPCs in DPM mode that are accessible for the user:

#!/usr/bin/env python

import zhmcclient
import requests.packages.urllib3

# Set these variables for your environment:
host = "<IP address or hostname of the HMC>"
userid = "<userid on that HMC>"
password = "<password of that HMC userid>"
verify_cert = False

session = zhmcclient.Session(host, userid, password, verify_cert=verify_cert)
client = zhmcclient.Client(session)
console = client.consoles.console

partitions = console.list_permitted_partitions()
for part in partitions:
    cpc = part.manager.parent
    print("{} {}".format(cpc.name, part.name))

Possible output when running the script:

P000S67B PART1
P000S67B PART2
P0000M96 PART1

For more example code, see the Python scripts in the examples directory of the Git repository, or the Tutorials section of this documentation.

To run the examples in the examples directory, you either need to set up an HMC inventory file and an HMC vault file to define the target HMC, or you can specify the HMC related parameters in the example scripts directly.

1.7. Versioning

This documentation applies to version 1.16.1 of the zhmcclient package. You can also see that version in the top left corner of this page.

The zhmcclient package uses the rules of Semantic Versioning 2.0.0 for its version.

The package version can be accessed by programs using the zhmcclient.__version__ variable [1]:

zhmcclient._version.__version__ = '1.16.1'

The full version of this package including any development levels, as a string.

Possible formats for this version string are:

  • “M.N.P.dev1”: A not yet released version M.N.P

  • “M.N.P”: A released version M.N.P

This documentation may have been built from a development level of the package. You can recognize a development version of this package by the presence of a “.devD” suffix in the version string. Development versions are pre-versions of the next assumed version that is not yet released. For example, version 0.1.2.dev25 is development pre-version #25 of the next version to be released after 0.1.1. Version 1.1.2 is an assumed next version, because the actually released next version might be 0.2.0 or even 1.0.0.

1.8. Compatibility

In this package, compatibility is always seen from the perspective of the user of the package. Thus, a backwards compatible new version of this package means that the user can safely upgrade to that new version without encountering compatibility issues.

This package uses the rules of Semantic Versioning 2.0.0 for compatibility between package versions, and for deprecations.

The public API of this package that is subject to the semantic versioning rules (and specificically to its compatibility rules) is the API described in this documentation.

Violations of these compatibility rules are described in section Change log.

1.9. Deprecations

Deprecated functionality is marked accordingly in this documentation and in the Change log, and is made visible at runtime by issuing Python warnings of type DeprecationWarning (see warnings for details).

Since Python 2.7, DeprecationWarning warnings are suppressed by default. They can be shown for example in any of these ways:

  • by specifying the Python command line option:

    -W default

  • by invoking Python with the environment variable:


  • by issuing in your Python program:

    warnings.filterwarnings(action='default', category=DeprecationWarning)

It is recommended that users of this package run their test code with DeprecationWarning warnings being shown, so they become aware of any use of deprecated functionality.

It is even possible to raise an exception instead of issuing a warning message upon the use of deprecated functionality, by setting the action to 'error' instead of 'default'.

1.10. Reporting issues

If you encounter any problem with this package, or if you have questions of any kind related to this package (even when they are not about a problem), please open an issue in the zhmcclient issue tracker.

It is helpful if you include debug information in the issue, that can be printed as in the following example:

$ python -c "import zhmcclient; print(zhmcclient.debuginfo())"
os_name: Darwin
os_version: 20.6.0
cpu_arch: x86_64
bit_size: 64
unicode_size: wide
python_impl: CPython
python_impl_version: 3.9.12
python_version: 3.9.12
zhmcclient_version: 1.4.0

1.11. License

This package is licensed under the Apache 2.0 License.