lvmconf

Table of Contents

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

Description

The lvmconf module delivers two main sets of functionality:

1. A resource type for directly managing entries in lvm.conf called lvm_config.
2. Pre-built logic to emulate the behavior of the lvmconf used to configure a system for HA LVM.

Setup

What lvmconf affects

1 - Packages

When enabled lvmconf will attempt to install the lvm2 package. Note that hiera defaults exist for RedHat 7 family operating systems, however, other operating systems will need to have the package_name parameter specified.

2 - lvm config

This class includes a provider for manipulating entries in /etc/lvm/lvm.conf using the lvmconfig command. Depending on the mode selected in the main class several configuration directives will be updated automatically. Currently this is limited to the following:

• global/use_lvmetad - Controls the use of the LVM metadata daemon. When HA LVM is configured this must be disabled
• global/locking_type - Controls the locking method used by LVM. This is needs to be set to standard locking for both halvm and standard modes of operation.

When halvm is enabled it is also important to configure the activation/volume_list parameter. This provides a white-list of volume groups which are safe for LVM to automatically import. Obviously any volumes which are part of an HA LVM scenario should be excluded from this list.

2 - Services

The state of the following services is managed automatically when mode is changed:

• metad - the lvm metadata daemon (lvmetad). In a standard system without HA LVM this daemon is used to accelerate lvm query commands by caching states in memory. This must be disabled when used with HA LVM

Additionally, if enabled, this class can automatically regenerate the initramfs to incorporate the changes to lvm.conf.

Beginning with lvmconf

On a RedHat 7 based operating system enabling standard configuration can be performed via the following simple call:

class { 'lvmconf':
  manage_package => true,
  mode           => 'standard',
}

Usage

The following examples assume a RedHat 7 based operating system. If a different operating system is used which does not have module hiera data additional parameters will need to be specified.

Enabling HA LVM

class { 'lvmconf':
  mode             => 'halvm'
  manage_initramfs => true,
  local_vgs        => [ 'rootvg' ],
}

Alternatively the same configuration can be performed via hiera.

lvmconf::mode: 'halvm'
lvmconf::manage_initramfs: true
lvmconf::local_vgs:
  - 'rootvg'

include lvmconf

Enabling Standard LVM

class { 'lvmconf':
  mode             => 'standard'
  manage_initramfs => true,
}

Alternatively the same configuration can be performed via hiera.

lvmconf::mode: 'standard'
lvmconf::manage_initramfs: true

include lvmconf

Limitations

• Enabling / disabling clvmd or cmirrord is currently not supported by this module.
• Initramfs updates are limited to dracut, however, other generators such as genkernel likely could be added.
• When lvm.conf parameters are modified there is no way to automatically reset them to default values. Such changes must be carried out directly on the target nodes.

Development

See the contributing guide.

Contributors

Check out the contributor list.

Reference

Table of Contents

Classes

• lvmconf: Performs basic management of LVM in a RedHat environment.
• lvmconf::config: Enforces lvm.conf based on lvmconf mode flags
• lvmconf::install: Install the lvm package if specified
• lvmconf::service: Manage the state of each LVM related service based on lvmconf mode

Resource types

• lvm_config: Type to manage entries in the /etc/lvm/lvm.conf config file via the lvmconfig (aka lvm config) command. Example: ```puppet lvm_config { '

Data types

• Lvmconf::InitramfsType: List of valid initramfs provider types
• Lvmconf::Mode: List of valid modes for LVM execution
• Lvmconf::Service: List of valid lvm related service names

Classes

lvmconf

Ensures that LVM is configured correctly on each

Examples

Trivial configuration of 'standard' mode

include lvmconf

Install package and enable HA LVM

class { 'lvmconf':
  systemd        => true,
  service_map    => {'metad' => 'lvm2-lvmetad'},
  manage_package => true,
  mode           => 'halvm',
  package_name   => 'lvm',
  local_vgs      => [ 'rootvg', 'nonclustervg' ],
}

Parameters

The following parameters are available in the lvmconf class:

• systemd
• service_map
• mode
• manage_package
• package_name
• manage_initramfs
• initramfs_type
• local_vgs

systemd

Data type: Boolean

Indicates whether this system uses systemd or sysv as it's init system. Different services will be manipulated depending on the value of this parameter.

service_map

Data type: Hash[Lvmconf::Service, String]

A hash mapping general names of LVM services to their OS/init system specific variants. Currently only the 'metad' entry is used directly.

Default value: {}

mode

Data type: Lvmconf::Mode

Configures the local LVM instance operation mode. See man lvmconf for more detail.

Default value: 'standard'

manage_package

Data type: Boolean

When true puppet will attempt to install the lvm2 package on this host.

Default value: false

package_name

Data type: Optional[String[1]]

Name of the LVM2 package for retrieval by the local package manager on the target system. Operating systems which are explicitly supported have hiera configured defaults for this parameter. It is mandatory when manage_package is true.

Default value: undef

manage_initramfs

Data type: Boolean

When true the local initramfs will be regenerated to take the changes to lvm.conf into account.

Default value: false

initramfs_type

Data type: Lvmconf::InitramfsType

Indicates the type of initramfs to be modified. Currently, only dracut is supported by this module.

Default value: 'dracut'

local_vgs

Data type: Array[String]

Whitelist of local-only volume groups which will be automatically imported by LVM. Each entry in this array will be added to the 'activation/volume_list' array in lvm.conf. This is critical when halvm or clustered LVM are enabled.

Default value: []

lvmconf::config

Enforces lvm.conf based on lvmconf mode flags

lvmconf::install

Install the lvm package if specified

lvmconf::service

Manage the state of each LVM related service based on lvmconf mode

Resource types

lvm_config

Type to manage entries in the /etc/lvm/lvm.conf config file via the lvmconfig (aka lvm config) command.

Example:

lvm_config { 'activation/volume_list':
  value  => [\"vg1\",\"vg2\"],
}

Properties

The following properties are available in the lvm_config type.

value

Data to be stored as the value for the specified Section/Setting key. Some validation is performed by lvmconfig during the apply process. If an error can be detected the provider will also generate a failure during the apply.

Parameters

The following parameters are available in the lvm_config type.

• include_comments
• name
• provider

include_comments

Valid values: true, false, yes, no

When true full descriptive comments will be included in the resulting lvm config file. Note that currently this is all or nothing. If you want to ensure comments are not included make sure you disable this for every instance of lvm_config!

Default value: true

name

namevar

The Section/Setting key string which corresponds to the desired variable. See the output of lvmconfig -l for reference. Values are not validated, however, the keys themselves are tested prior to creating the entry.

provider

The specific backend to use for this lvm_config resource. You will seldom need to specify this --- Puppet will usually discover the appropriate provider for your platform.

Data types

Lvmconf::InitramfsType

List of valid initramfs provider types

Alias of Enum['dracut']

Lvmconf::Mode

List of valid modes for LVM execution

Alias of Enum['halvm', 'cluster', 'standard']

Lvmconf::Service

List of valid lvm related service names

Alias of Enum['metad', 'lvm', 'monitor']

Changelog

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

0.1.1 (2023-07-03)

Feature (1 change)

• feat: redhat 8 & 9 support (merge request)

Maintenance (1 change)

• maint: pdk framework update (merge request)