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Bug 1861667

Summary:	[CBT] Copy all bitmaps from the previous top layer to the new layer when cold snapshot is taken for a VM that contains incremental backups
Product:	[oVirt] ovirt-engine	Reporter:	Eyal Shenitzky <eshenitz>
Component:	BLL.Storage	Assignee:	Eyal Shenitzky <eshenitz>
Status:	CLOSED CURRENTRELEASE	QA Contact:	Ilan Zuckerman <izuckerm>
Severity:	high	Docs Contact:
Priority:	unspecified
Version:	4.4.1	CC:	bugs, dfodor, nsoffer, sfishbai
Target Milestone:	ovirt-4.4.3	Flags:	pm-rhel: ovirt-4.4+
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	vdsm-4.40.32	Doc Type:	If docs needed, set a value
Doc Text:	When creating a snapshot while the VM is not running, the host needs to copy the bitmaps chain from the base volume to the newly created top volume. The copy of the bitmaps is done using the new 'qemu-img bitmaps' command. This operation is transparent to the user.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-11-11 06:42:26 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	Storage	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1804593, 1877209
Bug Blocks:

Description Eyal Shenitzky 2020-07-29 08:28:23 UTC

Description of problem:

When incremental backup introduced as a tech preview there was a known libvirt bug 1804593 for creating a cold VM snapshot when the VM contains also incremental backups.

In this case, the backup history will become useless since qemu
libvirt and qemu does not have an active bitmap at this point and maybe the result will be successful but wrong backup missing all the data written after the point of the snapshot.


Version-Release number of selected component (if applicable):
4.4.1

How reproducible:
100%

Steps to Reproduce:
1. Create a VM with disks
2. Run the VM
3. Create an incremental backups for the VM
4. Power off the VM
5. Create a snapshot for the VM
6. Run the VM
7. Create another incremental backup for the VM

Actual results:
The backup that was taken after the cold snapshot was created is wrong.

Expected results:
Incremental backup that created after a cold snapshot should work.

Additional info:

Comment 1 Ilan Zuckerman 2020-10-12 13:05:15 UTC

Verified on rhv-4.4.3-8 according steps from description

Comment 2 Sandro Bonazzola 2020-11-11 06:42:26 UTC

This bugzilla is included in oVirt 4.4.3 release, published on November 10th 2020.

Since the problem described in this bug report should be resolved in oVirt 4.4.3 release, it has been closed with a resolution of CURRENT RELEASE.

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