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Bug 1143872

Summary: [RFE] vdsm: QCOW2 v3 Image Format
Product: [oVirt] vdsm Reporter: Allon Mureinik <amureini>
Component: RFEsAssignee: Maor <mlipchuk>
Status: CLOSED CURRENTRELEASE QA Contact: Kevin Alon Goldblatt <kgoldbla>
Severity: high Docs Contact:
Priority: medium    
Version: ---CC: apinnick, bazulay, bgraveno, bmcclain, bugs, eheftman, fkust, fsimonce, knoel, lsurette, mgoldboi, mkalinin, mlipchuk, nsoffer, pdwyer, ratamir, rbalakri, scohen, shipatil, s.kieske, srevivo, tnisan, ykaul, ylavi
Target Milestone: ovirt-4.1.0-betaKeywords: FutureFeature
Target Release: ---Flags: rule-engine: ovirt-4.1+
gklein: testing_plan_complete+
ylavi: planning_ack+
rule-engine: devel_ack+
ratamir: testing_ack+
Hardware: Unspecified   
OS: Unspecified   
URL: https://github.com/maorlipchuk/ovirt-site/blob/cdbbfa5250af0e207ff151af67f188b3451d4c33/source/develop/release-management/features/storage/qcow2v3.html.md
Whiteboard:
Fixed In Version: hc Doc Type: Enhancement
Doc Text:
This release introduces QCOW2 v3 which has a compatibility level of 1.1. This enables the QEMU to use this volume in a more efficient way, with its improved performance capabilities. In addition, it is fully backwards-compatible with the QCOW2 feature set, it is easy to upgrade from QCOW2 v2 to QCOW2 v3, and it supports extensibility.
Story Points: ---
Clone Of: Environment:
Last Closed: 2017-02-15 14:54:22 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: 821546, 1417460    
Bug Blocks: 827529, 1080372, 1185830, 1415658    

Description Allon Mureinik 2014-09-18 07:47:03 UTC
Description of problem:
Newer QEMU versions support a new format of QCow2[1], which is not backwards compatible, and currently not supported in oVirt [2].

Since this new format offers many improvements (most notably zero clusters), we'd want to utilize it. This would require a new storage format in order to differentiate domains which allow this format and domains that do not.

Having a new domain format will also serve to streamline VDSM operations without an SPM, and prevent ugly hacks to determine whether we have one running or not.

[1] http://qemu.weilnetz.de/qemu-doc.html#disk_005fimages_005fformats
[2] See bug 1139707.

Comment 1 Allon Mureinik 2014-09-18 07:49:34 UTC
Open issue - what to do with pre-existing images when upgrading V3 to V4?
Offhand, there are several issues:

1. Nothing. Leave them as is, and just create new images with compat=1.1
2. Option #1 + a manual tool to "upgrade" images
3. Option #1 + engine support to "upgrade" images (disk -> right click -> upgrade)
4. Upgrade all of them synchronously when upgrading the domain.

Comment 2 Allon Mureinik 2014-12-30 08:44:58 UTC
*** Bug 827528 has been marked as a duplicate of this bug. ***

Comment 3 Allon Mureinik 2015-01-24 09:49:24 UTC
*** Bug 827529 has been marked as a duplicate of this bug. ***

Comment 4 Allon Mureinik 2015-04-27 11:30:05 UTC
Will be handled after removing SPM, need to see how this fits the timeline

Comment 15 Yaniv Kaul 2016-11-29 20:34:18 UTC
I thought most of the work is already done by Maor?

Comment 16 Maor 2016-12-03 13:10:25 UTC
The current status regarding this RFE is as follow:
1. Upgrading a DC to 4.1 should upgrade all data storage domains to V4.
2. All new volumes created on a 4.1 Data Center should be created with qcow version 1.1. That includes new disks, snapshots, Templates or VMs based on Templates (only the active volumes if thin provisioned)
Old volumes will be configured with 0.10 compat level.
3. A user will be able to check its disk's qcow version through REST:
http://localhost:8080/ovirt-engine/api/storagedomains/1234/disks/
4. If a user will want to upgrade its disk's qcow version he can use the REST API upgrade to amend the disk's qcow compat to 1.1

I will add the relevant patches to this bug so it can be better tracked.

Comment 17 Yaniv Lavi 2016-12-11 15:42:24 UTC
Should be MODIFIED?

Comment 18 Maor 2016-12-11 19:17:18 UTC
(In reply to Yaniv Dary from comment #17)
> Should be MODIFIED?

yes

Comment 20 Emma Heftman 2017-01-22 09:25:53 UTC
Hi Maor
Is there a need to update any of the documentation with this new version of QCOW2?

Comment 21 Maor 2017-01-24 15:01:57 UTC
(In reply to emma heftman from comment #20)
> Hi Maor
> Is there a need to update any of the documentation with this new version of
> QCOW2?

Yes, we should indicate that new volumes on DC 4.1 will be with qcow compat of 1.1 as described in here: http://www.ovirt.org/develop/release-management/features/storage/qcow2v3/

Comment 22 Kevin Alon Goldblatt 2017-02-01 16:19:23 UTC
MOVING TO VERIFIED

Comment 23 Avital Pinnick 2017-07-25 06:17:30 UTC
Removing doc text because this bug is duplicated in the release notes.

Comment 24 Franta Kust 2019-05-07 13:41:26 UTC
Sync with Jira