Bug 977767

Summary:	there is wrong backing file specified for making external snapshot with vmdk format disk
Product:	Red Hat Enterprise Linux 6	Reporter:	Sibiao Luo <sluo>
Component:	qemu-kvm	Assignee:	Fam Zheng <famz>
Status:	CLOSED ERRATA	QA Contact:	Virtualization Bugs <virt-bugs>
Severity:	medium	Docs Contact:
Priority:	low
Version:	6.5	CC:	acathrow, bsarathy, chayang, famz, flang, juzhang, michen, mkenneth, qzhang, virt-maint, xfu
Target Milestone:	rc
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	qemu-kvm-0.12.1.2-2.382.el6	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2013-11-21 07:01:29 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:

Description Sibiao Luo 2013-06-25 09:48:55 UTC

Description of problem:
mkae a vmdk format disk, then create external snapshot with vmdk format disk, check the snapshot file that there is wrong backing file specified for it.

Version-Release number of selected component (if applicable):
host info:
2.6.32-392.el6.x86_64
qemu-kvm-0.12.1.2-2.376.el6.x86_64

How reproducible:
100%

Steps to Reproduce:
1.create a vmdk format disk.
# qemu-img create -f vmdk vmdk-data-disk.vmdk 10G
Formatting 'vmdk-data-disk.vmdk', fmt=vmdk size=10737418240 compat6=off zeroed_grain=off 
# qemu-img info vmdk-data-disk.vmdk 
image: vmdk-data-disk.vmdk
file format: vmdk
virtual size: 10G (10737418240 bytes)
disk size: 12K
2.make external snapshot with vmdk format.
# qemu-img create -f vmdk -b vmdk-data-disk.vmdk vmdk-data-snapshot1
3.check the snapshot file info.
# qemu-img info vmdk-data-snapshot1

Actual results:
after step 2, make external snapshot with vmdk format successfully.
# qemu-img create -f vmdk -b vmdk-data-disk.vmdk vmdk-data-snapshot1Formatting 'vmdk-data-snapshot1', fmt=vmdk size=10737418240 backing_file='vmdk-data-disk.vmdk' compat6=off zeroed_grain=off 
after step 3, there is wrong backing file specified for it.
# qemu-img info vmdk-data-snapshot1
image: vmdk-data-snapshot1
file format: vmdk
virtual size: 10G (10737418240 bytes)
disk size: 12K
backing file: disk.vmdk             <--------it should be: vmdk-data-disk.vmdk

Expected results:
after step 3, there is correct backing file specified for snapshot file.

Additional info:
try the qcow2 format:
# qemu-img create -f qcow2 sluo-test 10G
Formatting 'sluo-test', fmt=qcow2 size=10737418240 encryption=off cluster_size=65536 
# qemu-img create -f qcow2 -b sluo-test -F qcow2 sluo-snapshot1
Formatting 'sluo-snapshot1', fmt=qcow2 size=10737418240 backing_file='sluo-test' backing_fmt='qcow2' encryption=off cluster_size=65536 
# qemu-img info sluo-snapshot1
image: sluo-snapshot1
file format: qcow2
virtual size: 10G (10737418240 bytes)
disk size: 136K
cluster_size: 65536
backing file: sluo-test          <---------correctly

Comment 1 Fam Zheng 2013-07-03 00:51:45 UTC

*** Bug 977774 has been marked as a duplicate of this bug. ***

Comment 5 Sibiao Luo 2013-07-30 06:12:29 UTC

Verify this issue on qemu-kvm-0.12.1.2-2.382.el6.x86_64 that it can do external snapshot with vmdk format disk successfully.

host info:
2.6.32-401.el6.x86_64
qemu-kvm-0.12.1.2-2.382.el6.x86_64

# qemu-img create -f vmdk vmdk-data-disk.vmdk 10G
Formatting 'vmdk-data-disk.vmdk', fmt=vmdk size=10737418240 compat6=off zeroed_grain=off 
# qemu-img info vmdk-data-disk.vmdk 
image: vmdk-data-disk.vmdk
file format: vmdk
virtual size: 10G (10737418240 bytes)
disk size: 12K
# qemu-img create -f vmdk -b vmdk-data-disk.vmdk vmdk-data-snapshot1
Formatting 'vmdk-data-snapshot1', fmt=vmdk size=10737418240 backing_file='vmdk-data-disk.vmdk' compat6=off zeroed_grain=off 
# qemu-img info vmdk-data-snapshot1
image: vmdk-data-snapshot1
file format: vmdk
virtual size: 10G (10737418240 bytes)
disk size: 12K
backing file: vmdk-data-disk.vmdk
# qemu-img create -f vmdk -b vmdk-data-snapshot1 vmdk-data-snapshot2
Formatting 'vmdk-data-snapshot2', fmt=vmdk size=10737418240 backing_file='vmdk-data-snapshot1' compat6=off zeroed_grain=off 
# qemu-img info vmdk-data-snapshot2
image: vmdk-data-snapshot2
file format: vmdk
virtual size: 10G (10737418240 bytes)
disk size: 12K
backing file: vmdk-data-snapshot1
# qemu-img create -f vmdk -b vmdk-data-snapshot2 vmdk-data-snapshot3
Formatting 'vmdk-data-snapshot3', fmt=vmdk size=10737418240 backing_file='vmdk-data-snapshot2' compat6=off zeroed_grain=off 
# qemu-img info vmdk-data-snapshot3
image: vmdk-data-snapshot3
file format: vmdk
virtual size: 10G (10737418240 bytes)
disk size: 12K
backing file: vmdk-data-snapshot2

Base on above, this issue has been fixed correctly. Set to verified status, please let me know if any mistake.

Best Regards,
sluo

Comment 8 errata-xmlrpc 2013-11-21 07:01:29 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, and where to find the updated
files, follow the link below.

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

http://rhn.redhat.com/errata/RHSA-2013-1553.html