dmmultipath

Table of Contents

1. Description
2. Setup - The basics of getting started with dmmultipath
   • Beginning with dmmultipath
3. Usage - Configuration options and additional functionality
4. Limitations - OS compatibility, etc.
5. Development - Guide for contributing to the module
   • Changelog
   • Contributors

Description

This module configures the DM Multipath module for a given device or set of devices.

Setup

There are no external dependencies for this module aside from standard system packages.

Beginning with dmmultipath

For this module to work the class must be included with at least one enabled storage controller.

class { 'dmmultipath':
  enabled_devices => ['ibm_2145'],
}

This can also be achieved via hiera.

---
dmmultipath::enabled_devices:
  - 'ibm_2145'

include 'dmmultipath'

Usage

The base configuration will provide sane defaults for the ibm_2145 device, enable the multipathd service at boot, and configure a 120 second timeout for all corresponding disk devices via udev. In addition, a regeneration of the initramfs for the current kernel can also be configured. This ensures that the appropriate multipath settings are available from the time of boot.

class { 'dmmultipath':
  regen_initramfs => true,
  enabled_devices => ['ibm_2145'],
}

Limitations

Operating System Support

• RedHat Family 7.x (CentOS and RHEL)

Controller Support

A full listing of supported types can be found in the definition of the Dmmultipath::SupportedModels type.

• IBM Spectrum Virtualize (SVC and Storwize) systems.

Development

TBD. Create an issue and we'll figure it out from there.

Contributors

Check out the contributor list.

Changelog

All feature updates for this module can be found in the changelog.

Reference

Table of Contents

Classes

• dmmultipath: A short summary of the purpose of this class
• dmmultipath::configure: Create the directory structure and each config file
• dmmultipath::install: Install any necessary packages for DM Multipath
• dmmultipath::service: Enable the multipathd service and regenerate initramfs (maybe)

Classes

dmmultipath

A description of what this class does

Examples

Default config enabling storwize

class { 'dmmultipath':
  enabled_devices => ['ibm_2145'],
}

Storwize with all options enabled

class { 'dmmultipath':
  find_multipaths     => true,
  user_friendly_names => true,
  udev_rules          => true,
  regen_initramfs     => true,
  config_dir          => '/etc/multipath/conf.d',
  udev_rules_dir      => '/etc/udev/rules.d',
  enabled_devices     => ['ibm_2145'],
}

Parameters

The following parameters are available in the dmmultipath class.

find_multipaths

Data type: Boolean

Sets the default parameter 'find_multipaths' to yes or no.

Default value: false

user_friendly_names

Data type: Boolean

Sets the default parameter 'user_friendly_names' to yes or no. This controls whether device alias names like 'mpatha' are automatically created.

Default value: true

udev_rules

Data type: Boolean

When enabled any udev rules relevant to enabled device types will be configured for this system.

Default value: true

regen_initramfs

Data type: Boolean

If enabled the initramfs will be regenerated for this machine. Note that this can be crucial for SAN boot systems as they need multipathing to be up and running when the system comes online.

Default value: false

config_dir

Data type: Stdlib::Absolutepath

Location of the multipath config files which will be read in and combined with the base '/etc/multipath.conf'. Typically this is '/etc/multipath/conf.d'.

Default value: '/etc/multipath/conf.d'

udev_rules_dir

Data type: Stdlib::Absolutepath

Location where additional udev rules should be defined. Typically this is '/etc/udev/rules.d'.

Default value: '/etc/udev/rules.d'

enabled_devices

Data type: Array[Dmmultipath::SupportedModels]

List of device types to enable on this system. Currently only ibm_2145 is supported by this module.

Default value: undef

dev_data

Data type: Hash[Dmmultipath::SupportedModels,Dmmultipath::Device]

This hash contains pre-configured lists of multipath 'device' directives. If a given device is enabled via $enabled_devices the corresponding values present in this hash will be used to create a file in the multipath config directory.

Default value: undef

dev_udev_data

Data type: Hash[Dmmultipath::SupportedModels,Dmmultipath::DeviceUdev]

Contains udev parameters for the provided device type. Note that this currently only supports SCSI timeouts. If udev_rules is enabled rules corresponding to the devices in $enabled_devices will be generated.

Default value: undef

packages

Data type: Array[String]

List of packages which should be installed for proper multipathing functionality.

Default value: undef

dmmultipath::configure

Private class responsible for creating config files & directory structure

dmmultipath::install

A simple internal class which manages all install-time steps

dmmultipath::service

Private class which manages services and other post-config activity.

Changelog

All notable changes to this project will be documented in this file.

Release 0.1.2

Full Changelog

Features

• Updated PDK to version 1.13.x

Bugfixes

• Converted the initramfs generation code such that it operates via refreshonly instead of attempting to checksum the resulting file

Release 0.1.1

Full Changelog

Features

• Updated PDK to version 1.9.x

Bugfixes

• Switched package declaration ensure statement from 'installed' to 'present' for compatibility with the stdlib function ensure_packages

Release 0.1.0

Features

• Support for IBM Storwize / SVC

Bugfixes

• None yet...

Known Issues

• None known...