Bug 692443

Summary: start domain will hang for several minutes after revert to a shutdown snapshot
Product: Red Hat Enterprise Linux 6 Reporter: weizhang <weizhan>
Component: libvirtAssignee: Eric Blake <eblake>
Status: CLOSED INSUFFICIENT_DATA QA Contact: Virtualization Bugs <virt-bugs>
Severity: medium Docs Contact:
Priority: medium    
Version: 6.1CC: dallan, dyuan, eblake, gren, llim, mzhan, nzhang, rwu, yoyzhang
Target Milestone: rc   
Target Release: ---   
Hardware: x86_64   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2011-12-19 22:02:24 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:

Description weizhang 2011-03-31 11:37:25 UTC
Description of problem:
After revert to a shutdown snapshot, domain start will hang for 7-13 minute on my test. The domain I use is rhel6/6.1.

Version-Release number of selected component (if applicable):
kernel-2.6.32-125.el6.x86_64
qemu-kvm-0.12.1.2-2.153.el6.x86_64
libvirt-0.8.7-15.el6.x86_64


How reproducible:
100%

Steps to Reproduce:
1. Prepare a shutdown domain with qcow2 img
2. create a snapshot when domain is shutdown
virsh snapshot-create domain 
3. start the domain
virsh start domain
4. revert domain to a shutdown snapshot
virsh snapshot-revert domain snapshot-name
5. start domain
virsh start domain
  
Actual results:
virsh start will hang for several minutes

Expected results:
virsh start will succeed with no hang

Additional info:
domain xml
<domain type='kvm' id='21'>
  <name>vr-rhel6u1-x86_64-kvm</name>
  <uuid>468d7413-1e95-a3c2-caba-834af5736659</uuid>
  <memory>524288</memory>
  <currentMemory>524288</currentMemory>
  <vcpu>1</vcpu>
  <os>
    <type arch='x86_64' machine='rhel6.1.0'>hvm</type>
    <boot dev='hd'/>
  </os>
  <features>
    <acpi/>
    <apic/>
    <pae/>
  </features>
  <clock offset='utc'/>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>restart</on_crash>
  <devices>
    <emulator>/usr/libexec/qemu-kvm</emulator>
    <disk type='file' device='disk'>
      <driver name='qemu' type='qcow2'/>
      <source file='/var/lib/libvirt/images/vr-rhel6u1-x86_64-kvm'/>
      <target dev='hda' bus='ide'/>
      <alias name='ide0-0-0'/>
      <address type='drive' controller='0' bus='0' unit='0'/>
    </disk>
    <controller type='ide' index='0'>
      <alias name='ide0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>
    </controller>
    <interface type='network'>
      <mac address='52:54:00:37:50:c2'/>
      <source network='default'/>
      <target dev='vnet2'/>
      <model type='rtl8139'/>
      <alias name='net0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
    </interface>
    <serial type='pty'>
      <source path='/dev/pts/5'/>
      <target port='0'/>
      <alias name='serial0'/>
    </serial>
    <console type='pty' tty='/dev/pts/5'>
      <source path='/dev/pts/5'/>
      <target type='serial' port='0'/>
      <alias name='serial0'/>
    </console>
    <input type='mouse' bus='ps2'/>
    <graphics type='vnc' port='5902' autoport='yes' keymap='en-us'/>
    <sound model='ac97'>
      <alias name='sound0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
    </sound>
    <video>
      <model type='cirrus' vram='9216' heads='1'/>
      <alias name='video0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
    </video>
    <memballoon model='virtio'>
      <alias name='balloon0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/>
    </memballoon>
  </devices>
  <seclabel type='dynamic' model='selinux'>
    <label>system_u:system_r:svirt_t:s0:c473,c587</label>
    <imagelabel>system_u:object_r:svirt_image_t:s0:c473,c587</imagelabel>
  </seclabel>
</domain>

Comment 1 RHEL Program Management 2011-04-04 02:05:33 UTC
Since RHEL 6.1 External Beta has begun, and this bug remains
unresolved, it has been rejected as it is not proposed as
exception or blocker.

Red Hat invites you to ask your support representative to
propose this request, if appropriate and relevant, in the
next release of Red Hat Enterprise Linux.