RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.
Bug 1140984 - sub-element in <disk>...</disk> change after create external disk snapshot
Summary: sub-element in <disk>...</disk> change after create external disk snapshot
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Enterprise Linux 7
Classification: Red Hat
Component: libvirt
Version: 7.1
Hardware: Unspecified
OS: Unspecified
medium
medium
Target Milestone: rc
: ---
Assignee: Peter Krempa
QA Contact: Virtualization Bugs
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2014-09-12 07:35 UTC by Shanzhi Yu
Modified: 2015-03-05 07:44 UTC (History)
4 users (show)

Fixed In Version: libvirt-1.2.8-3.el7
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2015-03-05 07:44:25 UTC
Target Upstream Version:
Embargoed:


Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2015:0323 0 normal SHIPPED_LIVE Low: libvirt security, bug fix, and enhancement update 2015-03-05 12:10:54 UTC

Description Shanzhi Yu 2014-09-12 07:35:27 UTC
Description of problem:

sub-element in <disk>...</disk> change after create external disk snapshot

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

libvirt-1.2.7-2.el7.x86_64
libvirt-client-1.2.7-2.el7.x86_64


How reproducible:

100%

Steps to Reproduce:

1. Prepare a running guest 

# virsh dumpxml rhel7-qcow2 |grep disk -A 5 
..
    <disk type='file' device='disk'>
      <driver name='qemu' type='qcow2' cache='none'/>
      <source file='/var/lib/libvirt/images/rhel7-qcow2.img'/>
      <backingStore/>
      <target dev='vda' bus='virtio'/>
      <alias name='virtio-disk0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
    </disk>
..

2. create external disk snapshot 

# virsh snapshot-create-as rhel7-qcow2 ss --disk-only

3. check guest xml 

# virsh dumpxml rhel7-qcow2 |grep disk -A 8
 <disk type='file' device='disk'>
      <driver type='qcow2' cache='none'/>
      <source file='/var/lib/libvirt/images/rhel7-qcow2.ss'/>
      <backingStore type='file' index='1'>
        <format type='qcow2'/>
        <source file='/var/lib/libvirt/images/rhel7-qcow2.img'/>
        <backingStore/>
      </backingStore>
      <target dev='vda' bus='virtio'/>
      <alias name='virtio-disk0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
    </disk>

4. validate xml for running guest 

#virsh dumpxml rhel7-qcow2 > r7.xml
# virt-xml-validate r7.xml 
Relax-NG validity error : Extra element devices in interleave
r7.xml:1: element domain: Relax-NG validity error : Element domain failed to validate content
r7.xml fails to validate

5. destroy/start guest and re-check guest xml

# virsh destroy rhel7-qcow2;virsh start rhel7-qcow2 
Domain rhel7-qcow2 destroyed

Domain rhel7-qcow2 started

#virsh dumpxml rhel7-qcow2
...
   <disk type='file' device='disk'>
      <driver type='qcow2' cache='none'/>
      <source file='/var/lib/libvirt/images/rhel7-qcow2.ss'/>
      <backingStore type='file' index='1'>
        <format type='qcow2'/>
        <source file='/var/lib/libvirt/images/rhel7-qcow2.img'/>
        <backingStore/>
      </backingStore>
      <target dev='vda' bus='virtio'/>
      <alias name='virtio-disk0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
    </disk>
...


Actual results:

In step 3, <driver name='qemu' type='qcow2' cache='none'/> change to <driver type='qcow2' cache='none'/>

Expected results:

driver name='qemu' type='qcow2' should not change in step 3 or virt-xml-validate pass in step 4 

Additional info:

# grep "driverFormat" docs/schemas/*.rng  -A 12
docs/schemas/domaincommon.rng:        <ref name="driverFormat"/>
docs/schemas/domaincommon.rng-      </optional>
docs/schemas/domaincommon.rng-      <optional>
docs/schemas/domaincommon.rng-        <ref name="driverCache"/>
docs/schemas/domaincommon.rng-      </optional>
docs/schemas/domaincommon.rng-      <optional>
docs/schemas/domaincommon.rng-        <ref name="driverErrorPolicy"/>
docs/schemas/domaincommon.rng-      </optional>
docs/schemas/domaincommon.rng-      <optional>
docs/schemas/domaincommon.rng-        <ref name="driverRerrorPolicy"/>
docs/schemas/domaincommon.rng-      </optional>
docs/schemas/domaincommon.rng-      <optional>
docs/schemas/domaincommon.rng-        <ref name="driverIO"/>
--
docs/schemas/domaincommon.rng:  <define name="driverFormat">
docs/schemas/domaincommon.rng-    <attribute name="name">
docs/schemas/domaincommon.rng-      <ref name="genericName"/>
docs/schemas/domaincommon.rng-    </attribute>
docs/schemas/domaincommon.rng-    <optional>
docs/schemas/domaincommon.rng-      <attribute name='type'>
docs/schemas/domaincommon.rng-        <choice>
docs/schemas/domaincommon.rng-          <ref name='storageFormat'/>
docs/schemas/domaincommon.rng-          <value>aio</value> <!-- back-compat for 'raw' -->
docs/schemas/domaincommon.rng-        </choice>
docs/schemas/domaincommon.rng-      </attribute>
docs/schemas/domaincommon.rng-    </optional>
docs/schemas/domaincommon.rng-  </define>

Comment 1 Peter Krempa 2014-09-16 16:11:00 UTC
Fixed upstream:

commit 865421c94a63f43c0164d598a73226d0e4231c93
Author: Peter Krempa <pkrempa>
Date:   Tue Sep 16 12:55:32 2014 +0200

    util: storage: Copy driver type when initializing chain element
    
    virStorageSourceInitChainElement initializes a new storage chain element
    for use as a new disk source. If the new element doesn't contain the
    driver name, copy it from the old source.
    
    This fixes issue where a disk would forget the driver after a snapshot.

Comment 4 Shanzhi Yu 2014-09-19 06:57:17 UTC
Verify this bug with libvirt-1.2.8-3.el7.x86_64.
Steps as comment 0. 

line "<driver name='qemu' type='qcow2' cache='none'/>" doesn't change after create external disk snapshot

Comment 6 errata-xmlrpc 2015-03-05 07:44:25 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.

https://rhn.redhat.com/errata/RHSA-2015-0323.html


Note You need to log in before you can comment on or make changes to this bug.