Bug 1455834

Summary: Query of blkdeviotune returns something for group name when group name is not set actually.
Product: Red Hat Enterprise Linux 7 Reporter: Fangge Jin <fjin>
Component: libvirtAssignee: Libvirt Maintainers <libvirt-maint>
Status: CLOSED NOTABUG QA Contact: Virtualization Bugs <virt-bugs>
Severity: medium Docs Contact:
Priority: medium    
Version: 7.4CC: dyuan, jiyan, lmen, pkrempa, pzhang, rbalakri, xuzhang
Target Milestone: rc   
Target Release: ---   
Hardware: x86_64   
OS: Linux   
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Last Closed: 2017-05-26 14:20:19 UTC Type: Bug
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description Fangge Jin 2017-05-26 09:11:27 UTC
Description of problem:
Query of blkdeviotune returns something for group name when group name is not set actually.

Version-Release number of selected component (if applicable):
libvirt-3.2.0-6.virtcov.el7.x86_64

How reproducible:
100%

Steps to Reproduce:
1.# virsh start vm2

2.# virsh blkdeviotune vm2 vda --total-bytes-sec 2000

3.# virsh blkdeviotune vm2 vda 
total_bytes_sec: 2000
read_bytes_sec : 0
write_bytes_sec: 0
total_iops_sec : 0
read_iops_sec  : 0
write_iops_sec : 0
total_bytes_sec_max: 200
read_bytes_sec_max: 0
write_bytes_sec_max: 0
total_iops_sec_max: 0
read_iops_sec_max: 0
write_iops_sec_max: 0
size_iops_sec  : 0
group_name     : drive-virtio-disk0 ===> group_name should be empty
total_bytes_sec_max_length: 1
read_bytes_sec_max_length: 0
write_bytes_sec_max_length: 0
total_iops_sec_max_length: 0
read_iops_sec_max_length: 0
write_iops_sec_max_length: 0

4. # virsh dumpxml vm2|grep iotune -a2
...
      <iotune>
        <total_bytes_sec>2000</total_bytes_sec>
      </iotune>
...


Actual results:
In step3, query of blkdeviotune returns something for group name

Expected results:
query of blkdeviotune should return nothing for group name

Comment 1 Peter Krempa 2017-05-26 14:20:19 UTC
The group is reported by qemu, if any of the tuning options are set, since every disk is in it's own group unless configured explicitly.

libvirt should report the current configuration of qemu as it's reported in this case.