On Thu, Mar 24, 2016 at 7:51 PM, Christophe TREFOIS
<christophe.trefois(a)uni.lu> wrote:
Hi Nir,
And the second one is down now too. see some comments below.
> On 13 Mar 2016, at 12:51, Nir Soffer <nsoffer(a)redhat.com> wrote:
>
> On Sun, Mar 13, 2016 at 9:46 AM, Christophe TREFOIS
> <christophe.trefois(a)uni.lu> wrote:
>> Dear all,
>>
>> I have a problem since couple of weeks, where randomly 1 VM (not always the same)
becomes completely unresponsive.
>> We find this out because our Icinga server complains that host is down.
>>
>> Upon inspection, we find we can’t open a console to the VM, nor can we login.
>>
>> In oVirt engine, the VM looks like “up”. The only weird thing is that RAM usage
shows 0% and CPU usage shows 100% or 75% depending on number of cores.
>> The only way to recover is to force shutdown the VM via 2-times shutdown from the
engine.
>>
>> Could you please help me to start debugging this?
>> I can provide any logs, but I’m not sure which ones, because I couldn’t see
anything with ERROR in the vdsm logs on the host.
>
> I would inspect this vm on the host when it happens.
>
> What is vdsm cpu usage? what is the qemu process (for this vm) cpu usage?
vdsm cpu usage is going up and down to 15%.
qemu process usage for the VM was 0, except for 1 of the threads “stuck” at 100%, rest
was idle.
0% may be a deadlock, 100% a thread stuck in endless loop, but this is
just a wild guess.
>
> strace output of this qemu process (all threads) or a core dump can help qemu
> developers to understand this issue.
I attached an strace on the process for:
qemu 15241 10.6 0.4 4742904 1934988 ? Sl Mar23 131:41 /usr/libexec/qemu-kvm
-name test-ubuntu-uni-lu -S -machine pc-i440fx-rhel7.2.0,accel=kvm,usb=off -cpu
SandyBridge -m size=4194304k,slots=16,maxmem=4294967296k -realtime mlock=off -smp
4,maxcpus=64,sockets=16,cores=4,threads=1 -numa node,nodeid=0,cpus=0-3,mem=4096 -uuid
754871ec-0339-4a65-b490-6a766aaea537 -smbios type=1,manufacturer=oVirt,product=oVirt
Node,version=7-2.1511.el7.centos.2.10,serial=4C4C4544-0048-4610-8052-B4C04F575831,uuid=754871ec-0339-4a65-b490-6a766aaea537
-no-user-config -nodefaults -chardev
socket,id=charmonitor,path=/var/lib/libvirt/qemu/domain-test-ubuntu-uni-lu/monitor.sock,server,nowait
-mon chardev=charmonitor,id=monitor,mode=control -rtc
base=2016-03-23T22:06:01,driftfix=slew -global kvm-pit.lost_tick_policy=discard -no-hpet
-no-shutdown -boot strict=on -device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 -device
virtio-scsi-pci,id=scsi0,bus=pci.0,addr=0x4 -device
virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5 -drive
if=none,id=drive-ide0-1-0,readonly=on,format=raw,serial= -device
ide-cd,bus=ide.1,unit=0,drive=drive-ide0-1-0,id=ide0-1-0 -drive
file=/rhev/data-center/00000002-0002-0002-0002-0000000003d5/8253a89b-651e-4ff4-865b-57adef05d383/images/9d60ae41-bf17-48b4-b0e6-29625b248718/47a6916c-c902-4ea3-8dfb-a3240d7d9515,if=none,id=drive-virtio-disk0,format=qcow2,serial=9d60ae41-bf17-48b4-b0e6-29625b248718,cache=none,werror=stop,rerror=stop,aio=threads
-device
virtio-blk-pci,scsi=off,bus=pci.0,addr=0x6,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1
-netdev tap,fd=108,id=hostnet0,vhost=on,vhostfd=109 -device
virtio-net-pci,netdev=hostnet0,id=net0,mac=00:1a:4a:e5:12:0f,bus=pci.0,addr=0x3,bootindex=2
-chardev
socket,id=charchannel0,path=/var/lib/libvirt/qemu/channels/754871ec-0339-4a65-b490-6a766aaea537.com.redhat.rhevm.vdsm,server,nowait
-device
virtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel0,id=channel0,name=com.redhat.rhevm.vdsm
-chardev
socket,id=charchannel1,path=/var/lib/libvirt/qemu/channels/754871ec-0339-4a65-b490-6a766aaea537.org.qemu.guest_agent.0,server,nowait
-device
virtserialport,bus=virtio-serial0.0,nr=2,chardev=charchannel1,id=channel1,name=org.qemu.guest_agent.0
-device usb-tablet,id=input0 -vnc 10.79.2.2:76,password -device
cirrus-vga,id=video0,bus=pci.0,addr=0x2 -device
virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x7 -msg timestamp=on
http://paste.fedoraproject.org/344756/84131214
You connected only to one thread. I would try to use -f to see all threads,
or connect with gdb and get a backtrace of all threads.
Adding Kevin to suggest how to continue.
I think we need a qemu bug for this.
Nir
This is CentOS 7.2, latest patches and latest 3.6.4 oVirt.
Thank you for any help / pointers.
Could it be memory ballooning?
Best,
>
>>
>> The host is running
>>
>> OS Version: RHEL - 7 - 1.1503.el7.centos.2.8
>> Kernel Version: 3.10.0 - 229.14.1.el7.x86_64
>> KVM Version: 2.1.2 - 23.el7_1.8.1
>> LIBVIRT Version: libvirt-1.2.8-16.el7_1.4
>> VDSM Version: vdsm-4.16.26-0.el7.centos
>> SPICE Version: 0.12.4 - 9.el7_1.3
>> GlusterFS Version: glusterfs-3.7.5-1.el7
>
> You are running old versions, missing lot of fixes. Nothing specific
> to your problem
> but this lower the chance to get a working system.
>
> It would be nice if you can upgrade to ovirt-3.6 and report if it made
> any change.
> Or at lest latest ovirt-3.5.
>
>> We use a locally exported gluster as storage domain (eg, storage is on the same
machine exposed via gluster). No replica.
>> We run around 50 VMs on that host.
>
> Why use gluster for this? Do you plan to add more gluster servers in the future?
>
> Nir