Note: This bug is displayed in read-only format because the product is no longer active in Red Hat Bugzilla.

Bug 1628700

Summary:	[Docs] OSP10 and later needs more warning notes about raw image format being ONLY supported format with Ceph storage backend
Product:	Red Hat OpenStack	Reporter:	Steven DuChene <sduchene>
Component:	documentation	Assignee:	Laura Marsh <lmarsh>
Status:	CLOSED WONTFIX	QA Contact:	RHOS Documentation Team <rhos-docs>
Severity:	high	Docs Contact:
Priority:	low
Version:	10.0 (Newton)	CC:	dcadzow, johfulto, lmarsh, srevivo
Target Milestone:	---
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:
Clones:	1866082 (view as bug list)		Environment:
Last Closed:	2020-08-04 19:40:24 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:
Bug Blocks:	1866082

Description Steven DuChene 2018-09-13 18:17:28 UTC

Description of problem: In a OSP deployment if Ceph storage is used as the backend storage for glance images, the ONLY supported image format is raw. A note about this needs to be added to the OSP Architecture Guide document in the glance storage section where supported image formats are discussed. The relevant section is here:

https://access.redhat.com/documentation/en-us/red_hat_openstack_platform/10/html/architecture_guide/components#comp-image

The appropriate & relevant note contents can be seen can n the OSP Director Installation and Usage document here:

https://access.redhat.com/documentation/en-us/red_hat_openstack_platform/10/html-single/director_installation_and_usage/#sect-Planning_Storage

The exact text of the note says:

IMPORTANT
If you want to boot virtual machines in Ceph (ephemeral backend or boot from volume), the glance image format must be RAW format. Ceph does not support other image formats such as QCOW2 or VMDK for hosting a virtual machine disk.

This issue of supported image formats when using Ceph backend for glance image storage came up at a strategic NFV customer who had implemented their OSP deployment with qcow2 images even though they had a Ceph storage backend for glance images. So this note needs to have higher visability in the OSP documentation wherever image formats for glance are discussed.

Thanks

Version-Release number of selected component (if applicable): OSP10, OSP11, OSP12, OSP13, and beyond.

How reproducible:

Steps to Reproduce:
1.
2.
3.

Actual results:

Expected results:

Additional info:

Comment 1 John Fulton 2019-09-05 17:09:00 UTC

Perhaps we should mention that the conversion is possible as per the request in docbug 1610329:

If you want to boot virtual machines in Ceph (ephemeral backend or boot from volume), the Glance image format must be RAW format. Ceph does not support other image formats such as QCOW2 or VMDK for hosting a virtual machine disk. While it's possible to configure Glance to convert the QCOW2 image to RAW if a QCOW2 image is uploaded, the conversion will occur while booting the instance which will take time. Thus, there are benefits to converting the image to RAW before uploading.