[libvirt-users] libvirtd does not update VM .xml configurations on filesystem after virsh snapshot/blockcommit
Saso Tavcar
fast at ais42.net
Wed Jun 19 12:23:43 UTC 2019
Hi,
Recently We've upgraded some KVM hosts from Fedora 29 to Fedora 30 and
now experience broken VM configurations on filesystem after virsh blockcommit.
Commands "virsh dumpxml ..." and "virsh dumpxml --inactive ..." is showing diffrent configuration than the one on filesystem.
In case of restart libvirtd or system reboot, there are broken VM xml configurations on filesystem.
Everything is OK on Fedora 29 KVM hosts!
0. XML configurations before snapshot is taken (all good, nothing found)
[root at server1 ~]# cat /etc/libvirt/qemu/somedomain.com.ncloud.xml| grep BACK
[root at server1 ~]# cat /etc/libvirt/qemu/somedomain.com.ncloud.xml| grep backingStore
[root at server1 ~]# /usr/bin/virsh --quiet dumpxml somedomain.com.ncloud|grep BACK
[root at server1 ~]# /usr/bin/virsh --quiet dumpxml somedomain.com.ncloud|grep backingStore
[root at server1 ~]# /usr/bin/virsh --quiet dumpxml --inactive somedomain.com.ncloud|grep BACK
[root at server1 ~]# /usr/bin/virsh --quiet dumpxml --inactive somedomain.com.ncloud|grep backingStore
1. When VM snapshot is taken with (all OK)
/usr/bin/virsh --quiet snapshot-create-as --domain somedomain.com.ncloud ....
there is a change of configuration, active, inactive and filesystem:
- active (virsh dumpxml)
[root at server1 ~]# /usr/bin/virsh --quiet dumpxml somedomain.com.ncloud|grep BACK
<source file='/Virtualization/linux/somedomain.com/somedomain.com.ncloud.qcow2-BACKUPING_NOW'/>
<source file='/Virtualization/linux/somedomain.com/somedomain.com.ncloud-swap.qcow2-BACKUPING_NOW'/>
<source file='/Virtualization/linux/somedomain.com/somedomain.com.ncloud-data1.qcow2-BACKUPING_NOW'/>
<source file='/Virtualization/linux/somedomain.com/somedomain.com.ncloud-data2.qcow2-BACKUPING_NOW'/>
[root at server1 ~]# /usr/bin/virsh --quiet dumpxml somedomain.com.ncloud|grep backingStore
<backingStore type='file'>
</backingStore>
<backingStore type='file'>
</backingStore>
<backingStore type='file'>
</backingStore>
<backingStore type='file'>
</backingStore>
- inactive (virsh dumpxml --inactive)
[root at server1 ~]# /usr/bin/virsh --quiet dumpxml --inactive somedomain.com.ncloud|grep BACK
<source file='/Virtualization/linux/somedomain.com/somedomain.com.ncloud.qcow2-BACKUPING_NOW'/>
<source file='/Virtualization/linux/somedomain.com/somedomain.com.ncloud-swap.qcow2-BACKUPING_NOW'/>
<source file='/Virtualization/linux/somedomain.com/somedomain.com.ncloud-data1.qcow2-BACKUPING_NOW'/>
<source file='/Virtualization/linux/somedomain.com/somedomain.com.ncloud-data2.qcow2-BACKUPING_NOW'/>
[root at server1 ~]# /usr/bin/virsh --quiet dumpxml --inactive somedomain.com.ncloud|grep backingStore
<backingStore type='file'>
</backingStore>
<backingStore type='file'>
</backingStore>
<backingStore type='file'>
</backingStore>
<backingStore type='file'>
</backingStore>
- XML configuration on filesystem has changed
[root at server1 ~]# ls -al /etc/libvirt/qemu/somedomain.com.ncloud.xml
-rw-------. 1 root root 6260 Jun 18 23:00 /etc/libvirt/qemu/somedomain.com.ncloud.xml
[root at server1 ~]# cat /etc/libvirt/qemu/somedomain.com.ncloud.xml |grep BACK
<source file='/Virtualization/linux/somedomain.com/somedomain.com.ncloud.qcow2-BACKUPING_NOW'/>
<source file='/Virtualization/linux/somedomain.com/somedomain.com.ncloud-swap.qcow2-BACKUPING_NOW'/>
<source file='/Virtualization/linux/somedomain.com/somedomain.com.ncloud-data1.qcow2-BACKUPING_NOW'/>
<source file='/Virtualization/linux/somedomain.com/somedomain.com.ncloud-data2.qcow2-BACKUPING_NOW'/>
[root at server1 ~]# cat /etc/libvirt/qemu/somedomain.com.ncloud.xml |grep backingStore
<backingStore type='file'>
</backingStore>
<backingStore type='file'>
</backingStore>
<backingStore type='file'>
</backingStore>
<backingStore type='file'>
</backingStore>
2. When VM backup is done, data merged with virsh backcommit ..." and snapshot deleted (NOT OK!!!)
...
/usr/bin/virsh --quiet blockcommit somedomain.com.ncloud sdd --active --pivot
/usr/bin/virsh --quiet snapshot-delete --domain somedomain.com.ncloud somedomain.com.ncloud-SNAPSHOT --metadata
there is a following state of VM configurations:
- active (virsh dumpxml),
[root at server1 ~]# /usr/bin/virsh --quiet dumpxml somedomain.com.ncloud|grep BACK ;;; OK
[root at server1 ~]# /usr/bin/virsh --quiet dumpxml somedomain.com.ncloud|grep backingStore ;;; why is there empty backingStore left ???
<backingStore/>
<backingStore/>
<backingStore/>
<backingStore/>
- inactive
[root at server1 qemu]# virsh dumpxml --inactive somedomain.com.ncloud |grep BACK ;;; OK
[root at server1 qemu]# virsh dumpxml --inactive somedomain.com.ncloud |grep backingStore ;;; OK
- XML on filesystem (.xml file on filesystem has not changed/reverted since snapshot has been taken - NOT OK!!!!, should be cleared of snapshot source file and backingStore)
[root at server1 ~]# ls -al /etc/libvirt/qemu/somedomain.com.ncloud.xml
-rw-------. 1 root root 6260 Jun 18 23:00 /etc/libvirt/qemu/somedomain.com.ncloud.xml
[root at server1 qemu]# cat somedomain.com.ns2.xml |grep BACK
<source file='/Virtualization/linux/somedomain.com/somedomain.com.ns2.qcow2-BACKUPING_NOW'/>
[root at server1 qemu]# cat somedomain.com.ns2.xml |grep backingStore
<backingStore type='file' index='1'>
</backingStore>
##############################################################################################################################################################################
- Fedora 29 has libvirt 4.7.0 and qemu 3.0.1:
[root at solaris1 ~]# rpm -qa |grep libvirt-daemon-kvm
libvirt-daemon-kvm-4.7.0-3.fc29.x86_64
[root at solaris1 ~]# rpm -qa |grep qemu-system-x86
qemu-system-x86-core-3.0.1-3.fc29.x86_64
qemu-system-x86-3.0.1-3.fc29.x86_64
- Fedora 30 has libvirt 5.1.0 and qemu 3.1.0:
[root at server1 ~]# rpm -qa |grep libvirt-daemon-kvm
libvirt-daemon-kvm-5.1.0-8.fc30.x86_64
[root at server1 ~]# rpm -qa |grep qemu-system-x86
qemu-system-x86-3.1.0-8.fc30.x86_64
qemu-system-x86-core-3.1.0-8.fc30.x86_64
For every VM from "virsh list" we do following steps (in script) for VM backup:
/usr/bin/virsh --quiet domblklist somedomain.com.ncloud
/usr/bin/virsh --quiet dumpxml --inactive somedomain.com.ncloud > /Backuping/VMs/Daily/somedomain.com.ncloud.xml
/usr/bin/virsh --quiet snapshot-create-as --domain somedomain.com.ncloud somedomain.com.ncloud-SNAPSHOT --diskspec sda,file=/Virtualization/linux/somedomain.com/somedomain.com.ncloud.qcow2-BACKUPING_NOW --diskspec sdb,file=/Virtualization/linux/somedomain.com/somedomain.com.ncloud-swap.qcow2-BACKUPING_NOW --diskspec sdc,file=/Virtualization/linux/somedomain.com/somedomain.com.ncloud-data1.qcow2-BACKUPING_NOW --diskspec sdd,file=/Virtualization/linux/somedomain.com/somedomain.com.ncloud-data2.qcow2-BACKUPING_NOW --disk-only --atomic --quiesce
/usr/bin/virsh --quiet snapshot-list somedomain.com.ncloud
/usr/bin/scp -p server1.somedomain.us:/Virtualization/linux/somedomain.com/somedomain.com.ncloud.qcow2 somedomain.com.ncloud.qcow2
/usr/bin/scp -p server1.somedomain.us:/Virtualization/linux/somedomain.com/somedomain.com.ncloud-swap.qcow2 somedomain.com.ncloud-swap.qcow2
/usr/bin/scp -p server1.somedomain.us:/Virtualization/linux/somedomain.com/somedomain.com.ncloud-data1.qcow2 somedomain.com.ncloud-data1.qcow2
/usr/bin/scp -p server1.somedomain.us:/Virtualization/linux/somedomain.com/somedomain.com.ncloud-data2.qcow2 somedomain.com.ncloud-data2.qcow2
/usr/bin/virsh --quiet blockcommit somedomain.com.ncloud sda --active --pivot
/usr/bin/virsh --quiet blockcommit somedomain.com.ncloud sdb --active --pivot
/usr/bin/virsh --quiet blockcommit somedomain.com.ncloud sdc --active --pivot
/usr/bin/virsh --quiet blockcommit somedomain.com.ncloud sdd --active --pivot
/usr/bin/virsh --quiet snapshot-delete --domain somedomain.com.ncloud somedomain.com.ncloud-SNAPSHOT --metadata
/usr/bin/ssh server1.somedomain.us "/usr/bin/rm /Virtualization/linux/somedomain.com/somedomain.com.ncloud.qcow2-BACKUPING_NOW"
/usr/bin/ssh server1.somedomain.us "/usr/bin/rm /Virtualization/linux/somedomain.com/somedomain.com.ncloud-swap.qcow2-BACKUPING_NOW"
/usr/bin/ssh server1.somedomain.us "/usr/bin/rm /Virtualization/linux/somedomain.com/somedomain.com.ncloud-data1.qcow2-BACKUPING_NOW"
/usr/bin/ssh server1.somedomain.us "/usr/bin/rm /Virtualization/linux/somedomain.com/somedomain.com.ncloud-data2.qcow2-BACKUPING_NOW"
/usr/bin/pigz --best --rsyncable somedomain.com.ncloud.qcow2
/usr/bin/pigz --best --rsyncable somedomain.com.ncloud-swap.qcow2
/usr/bin/pigz --best --rsyncable somedomain.com.ncloud-data1.qcow2
/usr/bin/pigz --best --rsyncable somedomain.com.ncloud-data2.qcow2
There is no error on script (commands) execution:
[root at server1 ~]# /Backuping/bin/simple_KVM_backup.pl --depth 7 --path Daily --hosting_server server1.somedomain.us
###Backuping VM somedomain.com.ncloud:
+ Moving somedomain.com.ncloud.xml.06 to somedomain.com.ncloud.xml.07.
+ Moving somedomain.com.ncloud.qcow2.gz.06 to somedomain.com.ncloud.qcow2.gz.07.
...
+ Disk snapshot somedomain.com.ncloud-SNAPSHOT for somedomain.com.ncloud ... Domain snapshot somedomain.com.ncloud-SNAPSHOT created
Name Creation Time State
-----------------------------------------------------------------------
somedomain.com.ncloud-SNAPSHOT 2019-06-18 23:00:04 +0200 disk-snapshot
Done!
+ Time scp start : 2019-06-18 23:00:05
somedomain.com.ncloud.qcow2 100% 20GB 401.3MB/s 00:51
Done!
somedomain.com.ncloud-swap.qcow2 100% 4097MB 483.5MB/s 00:08
Done!
somedomain.com.ncloud-data1.qcow2 100% 100GB 400.7MB/s 04:15
Done!
somedomain.com.ncloud-data2.qcow2 100% 100GB 440.6MB/s 03:52
Done!
+ Time scp end : 2019-06-18 23:09:14
+ Time blockcommit start : 2019-06-18 23:09:14
Successfully pivoted
Successfully pivoted
Successfully pivoted
Successfully pivoted
+ Time blockcommit end : 2019-06-18 23:09:16
+ Snapshot delete ... Domain snapshot somedomain.com.ncloud-SNAPSHOT deleted
Done!
+ Delete snapshot files ... Done!
+ Time compress start : 2019-06-18 23:09:17
Regards,
saso
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