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Bug 2056460

Summary:	Implement preallocated disks for oVirt in the OCP installer
Product:	OpenShift Container Platform	Reporter:	Janos Bonic <jpasztor>
Component:	Installer	Assignee:	Janos Bonic <jpasztor>
Installer sub component:	OpenShift on RHV	QA Contact:	Veronika Fuxova <vfuxova>
Status:	CLOSED ERRATA	Docs Contact:	Eli Marcus <emarcus>
Severity:	high
Priority:	high	CC:	emarcus, mburman
Version:	4.11
Target Milestone:	---
Target Release:	4.11.0
Hardware:	All
OS:	All
Whiteboard:
Fixed In Version:		Doc Type:	Enhancement
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2022-08-10 10:50:27 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2056454
Bug Blocks:	2035334

Description Janos Bonic 2022-02-21 10:01:10 UTC

As per RFE 2035334, this BZ is tracking the implementation of preallocated disks for the control plane nodes and the intially created worker nodes.

This implementation exposes 3 options in the install config. (See https://docs.openshift.com/container-platform/4.9/installing/installing_rhv/installing-rhv-customizations.html for details.)

- clone: creates virtual machines that are cloned from the template instead of linking it to the original. (Default so far was: false)
- sparse: creates a thin-provisioned disk. (Default so far was: true)
- format: lets users switch disk formats. Can be "raw" or "cow". Raw disks don't support backups, but may be better for sparse provisioning on the underlying storage system. (Default so far was: "cow")

Suggestion for default values in this BZ is welcome. Default values will only be applied to newly created install configs. When using an install config from a previous OCP version the old default values will still be applied.

Note: The installer creates the control plane nodes with the given settings and the initial machine set for worker nodes. The control plane node configuration cannot be changed after installation at this time. The machine set for worker nodes can be updated and worker nodes can be replaced after the installation for preallocated worker nodes.

This change is dependent on the Terraform provider supporting these flags, which is not tracked in Bugzilla: https://github.com/oVirt/terraform-provider-ovirt/pull/313

Comment 4 Veronika Fuxova 2022-05-23 14:09:29 UTC

Verified by testing these three configurations: 

Configuration 1

This installation should be performed without modifications to the install config. The flags on the control plane nodes should be:

cloned
sparse provisioned
QCOW2 format

Configuration 2

In this configuration we preallocate disks and the following configuration should be used.

controlPlane: 
  platform: 
    ovirt: 
      clone: true 
      sparse: false
      format: raw
compute: 
  platform: 
    ovirt: 
      clone: true 
      sparse: false
      format: raw


Configuration 3

controlPlane: 
  platform: 
    ovirt: 
      clone: false 
      sparse: true
      format: cow
compute: 
  platform: 
    ovirt: 
      clone: false 
      sparse: true
      format: cow

OCP version: 4.11.0-0.nightly-2022-05-18-053037

Platform: RHV 4.5.0.6-0.7.el8ev

IPI


Steps: 

Configuration 1: 
1. Created new install-config using Openshift installer. 
2. Ran Openshift installation using unmodified install-config
3. Verified relevant flags on control plane and worker nodes as follows:
 
Masters:

    - Disk format
            Expected: cow
            Actual: cow

    - Sparseness
            Expected: true (thin provision)
            Actual: true (thin provision)

    - Cloned from the template
            Expected: true (Clone/Independent)
            Actual: true (Clone/Independent)

Workers:

    - Disk format
            Expected: cow
            Actual: cow

    - Sparseness
            Expected: true (thin provision)
            Actual: true (thin provision)

    - Cloned from the template
            Expected: true (Clone/Independent)
            Actual: true (Clone/Independent)

 

Configuration 2: 
1. Modified install-config as outlined above. 
2. Ran Openshift installation using modified install-config
3. Verified relevant flags on control plane and worker nodes as follows:
 
Masters:   

    - Disk format
            Expected: raw 
            Actual: raw

    - Sparseness
            Expected: false (preallocated)
            Actual: false (preallocated) 

    - Cloned from the template
            Expected: true (Clone/Independent)
            Actual: true (Clone/Independent) 

Workers:  

    - Disk format
            Expected: raw 
            Actual: raw

    - Sparseness
            Expected: false (preallocated)
            Actual: false (preallocated) 

    - Cloned from the template
            Expected: true (Clone/Independent)
            Actual: true (Clone/Independent)  

             
Configuration 3: 
1. Modified install-config as outlined above. 
2. Ran Openshift installation using modified install-config
3. Verified relevant flags on control plane and worker nodes as follows:

Masters:

    - Disk format
            Expected: cow
            Actual: cow

    - Sparseness
            Expected: true (thin provision)
            Actual: true (thin provision)

    - Cloned from the template
            Expected: false (Thin/Dependent)
            Actual: false (Thin/Dependent)

Workers:

    - Disk format
            Expected: cow
            Actual: cow

    - Sparseness
            Expected: true (thin provision)
            Actual: true (thin provision)

    - Cloned from the template
            Expected: false (Thin/Dependent)
            Actual: false (Thin/Dependent)

Comment 6 Eli Marcus 2022-06-27 13:19:14 UTC

Documentation  - new PR 
 https://github.com/openshift/openshift-docs/pull/47085

Comment 7 errata-xmlrpc 2022-08-10 10:50:27 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory (Important: OpenShift Container Platform 4.11.0 bug fix and security update), and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHSA-2022:5069