Bug 711971

Summary: can not get block stats
Product: [Community] Virtualization Tools Reporter: casoul lee <lijingwei9060>
Component: libvirtAssignee: Osier Yang <jyang>
Status: CLOSED WONTFIX QA Contact:
Severity: high Docs Contact:
Priority: unspecified    
Version: unspecifiedCC: crobinso, dallan, jyang, xen-maint
Target Milestone: ---   
Target Release: ---   
Hardware: x86_64   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2011-11-23 02:42:41 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Attachments:
Description Flags
the vm libvirt xml file
none
libvirt log file none

Description casoul lee 2011-06-09 07:06:45 UTC 
Description of problem:
can not get block stats from attached disks.

Version-Release number of selected component (if applicable):
from 0.6.1 to 0.9.1
[root@bc-clc vms]# virsh version
Compiled against library: libvir 0.9.1
Using library: libvir 0.9.1
Using API: QEMU 0.9.1
Running hypervisor: QEMU 0.9.1

[root@bc-clc vms]# rpm -qa|grep kvm
kmod-kvm-83-224.el5.centos.1
kvm-qemu-img-83-224.el5.centos.1
etherboot-zroms-kvm-5.4.4-13.el5.centos
kvm-83-224.el5.centos.1


How reproducible:
1.create a vm: virsh create libvirt.xml
2.attach a disk:virsh attach-disk 3 /opt/vms/test.img vdb
3.virsh domblkstats 3 vdb
   error: Failed to get block stats 3 vdb
   error: internal error missing disk device alias name for vdb
4.while virsh domblkstats 3 vda
  vda rd_req 6667
  vda rd_bytes 154084864
  vda wr_req 9530
  vda wr_bytes 57196544


 Additional info:
I guess,libvirt does not get disk->info.alias while attching a disk.
Comment 1 casoul lee 2011-06-09 07:08:06 UTC 
Created attachment 503833 [details]
the vm libvirt xml file
Comment 2 Osier Yang 2011-06-10 06:34:01 UTC 
Can you test with debug log level turned on? when you attached the disk, you should see the "device string" which is constructed by libvirt in debug log:


    VIR_DEBUG("mon=%p device=%s fd=%d fdname=%s", mon, devicestr, fd,
              NULLSTR(fdname));

E.g. device=virtio-blk-pci,bus=pci.0,addr=0x6,drive=drive-virtio-disk1,id=virtio-disk1

The value for "id" in the end of the string actually is the value of "disk->info.alias".

It looks to me there is no reason the "disk->info.alias" is NULL, libvirt assigns its value when attaching the disk, if it fails on assigning its value, the disk attaching will fail earlier, means you won't see the disk attaching was successfull.

See "log_level" in "/etc/libvirt/libvirtd.conf" for how to set the debug log level.
Comment 3 casoul lee 2011-06-13 05:45:41 UTC 
I changed "log_level" in ""/etc/libvirt/libvirtd.conf" as attachment.
I got following logs :

11:43:13.072: 17759: debug : qemuCapsParseHelpStr:1037 : Version 0.9.1, cooked version 9001, flags 0x0000580f120efd7e
11:43:13.072: 17759: debug : qemuCapsParseHelpStr:1041 : KVM version 83 detected
11:43:13.072: 17759: info : virSecurityDACSetOwnership:99 : Setting DAC user and group on '/opt/vms/test.img' to '101:36'
11:43:13.072: 17759: debug : qemuMonitorAddPCIDisk:1715 : mon=0x12466d90 path=/opt/vms/test.img bus=virtio
11:43:13.072: 17759: debug : qemuMonitorTextCommandWithHandler:233 : Send command 'pci_add pci_addr=auto storage file=/opt/vms/test.img,if=virtio' for write with FD -1
11:43:13.072: 17759: debug : virEventPollUpdateHandle:144 : Update handle w=8 e=15
Comment 4 casoul lee 2011-06-13 05:46:45 UTC 
Created attachment 504366 [details]
libvirt log file

libvirt log file
Comment 5 casoul lee 2011-06-13 08:35:54 UTC 
this is log when detaching a disk ,libvirt does use pci_address ,not info.alias.

15:40:39.864: debug : virEventCalculateTimeout:314 : Calculate expiry of 2 timers
15:40:39.864: debug : virEventCalculateTimeout:344 : Timeout at 0 due in -1 ms
15:40:39.864: debug : virEventRunOnce:593 : Poll on 8 handles 0x2aaaac0015e0 timeout -1
15:40:39.864: debug : qemuMonitorRemovePCIDevice:1555 : mon=0x61c9eb0 domain=0 bus=0 slot=6 function=0
15:40:39.864: debug : qemuMonitorCommandWithHandler:338 : Send command 'pci_del pci_addr=0000:00:06' for write with FD -1
15:40:39.864: debug : virEventUpdateHandleImpl:147 : Update handle w=11 e=15
15:40:39.864: debug : virEventInterruptLocked:668 : Interrupting
15:40:39.864: debug : virEventRunOnce:595 : Poll got 1 event
15:40:39.864: debug : virEventDispatchTimeouts:405 : Dispatch 2
Comment 6 Osier Yang 2011-06-13 09:58:34 UTC 
Oh, it looks to me your qemu doesn't support "-device" yet, that's why the final command to attach a disk is "pci_add". libvirt doesn't generate "info.alias" for the disk attaching in this case, this is a bug of libvirt indeed.
Comment 7 casoul lee 2011-06-14 02:17:48 UTC 
what should I do now,update kvm?
Comment 8 Osier Yang 2011-06-14 02:31:46 UTC 
If it's urgent for you to bypass the problem, you can update your qemu to the one support "-device" flag. No need to update KVM.
Comment 9 Dave Allan 2011-11-23 02:42:41 UTC 
(In reply to comment #6)
> Oh, it looks to me your qemu doesn't support "-device" yet, that's why the
> final command to attach a disk is "pci_add". libvirt doesn't generate
> "info.alias" for the disk attaching in this case, this is a bug of libvirt
> indeed.

I think we are not likely ever to support such old versions of qemu, so I a closing as WONTFIX.