Bug 1650419

Summary:	[RFE] implement support for qcow2 internal snapshots without libvirt metadata
Product:	Red Hat Enterprise Linux 8	Reporter:	gaojianan <jgao>
Component:	libvirt	Assignee:	Peter Krempa <pkrempa>
Status:	CLOSED WONTFIX	QA Contact:	gaojianan <jgao>
Severity:	low	Docs Contact:
Priority:	low
Version:	8.1	CC:	dyuan, hhan, jsuchane, knoel, rbalakri, xuzhang
Target Milestone:	rc	Keywords:	FutureFeature
Target Release:	8.0
Hardware:	x86_64
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:
Clones:	1650420 (view as bug list)		Environment:
Last Closed:	2019-01-22 13:28:31 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:	1650420

Description gaojianan 2018-11-16 06:32:04 UTC

Description of problem:
“virsh snapshot-list“ with option --no-metadata can't show snapshots without metadata

Version-Release number of selected component (if applicable):
Linux test2 4.18.0-31.el8.x86_64 #1 SMP
libvirt-4.5.0-14.module+el8+2210+474b8474.x86_64

How reproducible:
100%

Steps to Reproduce:
1.Prepare a guest and take snapshots with option --no-metadata
# virsh snapshot-create-as rhel s1 --no-metadata
Domain snapshot s1 created
2.List the snapshot with option --no-metadata
# virsh snapshot-list rhel --no-metadata
 Name                 Creation Time             State
------------------------------------------------------------


Actual results:
There is no snapshot shown with snapshot-list --no-metadata.
Expected results:
Show the snapshots which is established in step 1.

Additional info:
There are some discussions about this question:
https://www.redhat.com/archives/libvir-list/2018-November/msg00045.html
https://www.redhat.com/archives/libvir-list/2018-November/msg00517.html

Comment 1 Peter Krempa 2018-11-16 09:15:34 UTC

This means implementing internal snapshot loading from qcow. Given that qemu's stance is that external snapshots are the way to go I don't expect much attention here, but it's a legitimately missing feature.

Comment 2 Peter Krempa 2019-01-22 13:28:31 UTC

The problems which would arise from attempting libvirt to deal with snapshots with no libvirt metadata (e.g. missing snapshot of the XML state) far outweigh the benefits of implementing this, thus I'll close this BZ for now.