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[libvirt-users] attach-interface not permanent?
by Dennis Jacobfeuerborn 23 Oct '12

23 Oct '12

Hi, I just created a new interface for a running Windows 2008 guest using the attach-interface command which succeeded and I could see the interface in the guest and in the dumpxml output. Then I switched the type to virtio in virt-manager after which I got the message that this change would only appear after the next guest shutdown so I went ahead and shut down the guest. After that the new interface was gone and no longer showed up in the dumpxml output. I'm confused because at no point was it mentioned that the interface would only be added temporarily and the man-page doesn't say anything to that effect either. This happened on a fresh Centos 6.3 system. Any ideas what is going on here? Regards, Dennis

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[libvirt-users] error: internal error lxc state driver is not active
by #█er 22 Oct '12

22 Oct '12

hi: I want to use libvirt with LXC, but when I use virsh -c lxc:/// to connect to lxc, it just print these errors: error: internal error lxc state driver is not active error: failed to connect to the hypervisor I searched these error message , but it seems that there is no helpful information . Could you help me solve this problem? Thanks :)

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[libvirt-users] Questions and a blockpull issue
by Abbas 21 Oct '12

21 Oct '12

Coming off of xen environment; still testing with kvm, just a few questions: 1. What is the roadmap for release of qemu-kvm 1.1 and libvirt 0.10.2 for el6, cause I had to compile from upstream to get the latest stuff. 2. Should not virt-manager show the sparsed disk size instead of actual reserved size of a vm? 3. Where is the virsh bash_completion conf.d file from upstream; since el6 rpm for it seems have tab completion built right into virsh shell. 4. Created a disk-only snapshot of a vm CO1 called capture1 but the syntax of blockpulling seems to be opposite from what has been advertised on Fedora and other relative wikis. Check below and the error with first blockpull command. [root@KVM libvirt]# virsh snapshot-create-as CO1 capture1 "CO1s first snapshot test" --disk-only --atomic [root@KVM libvirt]# virsh -d 0 blockpull CO1 --path /home/vms/co1.img --bandwidth 500 --base /home/vms/co1.capture1 blockpull: domain(optdata): CO1 blockpull: path(optdata): /home/vms/co1.img blockpull: bandwidth(optdata): 500 blockpull: base(optdata): /home/vms/co1.capture1 blockpull: found option <domain>: CO1 blockpull: <domain> trying as domain NAME error: invalid argument: No device found for specified path [root@KVM libvirt]# virsh -d 0 blockpull --domain CO1 --path /home/vms/co1.capture1 --base /home/vms/co1.img --verbose --wait blockpull: domain(optdata): CO1 blockpull: path(optdata): /home/vms/co1.capture1 blockpull: base(optdata): /home/vms/co1.img blockpull: verbose(bool): (none) blockpull: wait(bool): (none) blockpull: found option <domain>: CO1 blockpull: <domain> trying as domain NAME Block Pull: [100 %] Pull complete Best, Abbas.

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[libvirt-users] cpuset not affecting real pid placement
by Andrey Korolyov 18 Oct '12

18 Oct '12

Hi, At least on 0.10.2 setting a cpuset doesn`t match a real process placement - VM still consumes all available cores. VM config: .snip. <vcpu placement='static' cpuset='0-5,12-17'>12</vcpu> .snip. for cpuset in $(find /cgroup/cpuset/libvirt/qemu/vmid/ -name cpuset.cpus) ; do grep 0-5 $cpuset ; done got: empty responce, e.g. 0-23 in my setup expected: at least bounded vcpuX threads In neighbor 'cpu' group libvirt sets cfq weights just fine, so this is clearly a bug.

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[libvirt-users] Using libvirt to monitor virtual environment.
by Vinicius Gonçalves Braga 18 Oct '12

18 Oct '12

Hey, I am new with libvirt. I am working to create a program to monitor a virtual environment. I have seen some solutions that use libvirt. Is this API good to make monitoring operations? I didn't see operations that show the CPU or memory usage, at least in Java binding. Are there operations like these, or we have to calculate based on lower level informations?

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[libvirt-users] Create and revert to snapshot fails silently after device update on running domain
by Jasper Spit 18 Oct '12

18 Oct '12

Hi list, I'm having an issue with snapshot creation. Scenario: qemu 1.1 libvirt 0.9.12 I create a domain, and start it. The domain has 1 IDE cdrom device defined (see below). When started, I want to mount an ISO file to it. So I do updateDeviceFlags in libvirt-python or update-device in virsh (both have the same problem). This works fine, the ISO image becomes available to the domain. Now I create a snapshot on the still running domain using snapshotCreateXML in libvirt-python or snapshot-create in virsh. The command returns immediately without error (a normal snapshot takes several seconds to complete). If I revert to this snapshot this command also returns immediately without error, but the snapshot is not actually reverted to, the domain remains running in the same state as if nothing had happened (I test this by verifying console output and checking if a testfile is present on the domain). If I do not use the update device commands prior to creating a snapshot, all is well. If I remove the source from the cdrom device using update device, the snapshots work properly again. Any idea what causes this? Steps to reproduce using virsh: virsh # start 4d5d722b-864c-657e-0f39-55d1bafc760e Domain 4d5d722b-864c-657e-0f39-55d1bafc760e started virsh # snapshot-create 4d5d722b-864c-657e-0f39-55d1bafc760e Domain snapshot 1348653920 created virsh # snapshot-revert 4d5d722b-864c-657e-0f39-55d1bafc760e 1348653920 All is good, the snapshot is reverted to properly. Now I update the cdrom device: virsh # update-device 4d5d722b-864c-657e-0f39-55d1bafc760e deb.xml Device updated successfully virsh # snapshot-create 4d5d722b-864c-657e-0f39-55d1bafc760e Domain snapshot 1348654116 created Command returns instantly. virsh # snapshot-revert 4d5d722b-864c-657e-0f39-55d1bafc760e 1348654116 No errors, but the snapshot is not reverted to. Now I remove the <source .../> again and do an update-device. virsh # update-device 4d5d722b-864c-657e-0f39-55d1bafc760e deb-off.xml Device updated successfully virsh # snapshot-create 4d5d722b-864c-657e-0f39-55d1bafc760e Domain snapshot 1348654540 created virsh # snapshot-revert 4d5d722b-864c-657e-0f39-55d1bafc760e 1348654540 Snapshot is created and reverted to properly. virsh # dumpxml 4d5d722b-864c-657e-0f39-55d1bafc760e <domain type='kvm' id='135'> <name>4d5d722b-864c-657e-0f39-55d1bafc760e</name> <uuid>4d5d722b-864c-657e-0f39-55d1bafc760e</uuid> <memory unit='KiB'>786432</memory> <currentMemory unit='KiB'>786432</currentMemory> <vcpu placement='static'>1</vcpu> <os> <type arch='x86_64' machine='pc-1.1'>hvm</type> <boot dev='hd'/> <boot dev='cdrom'/> </os> <features> <acpi/> <apic/> <pae/> </features> <clock offset='utc'/> <on_poweroff>destroy</on_poweroff> <on_reboot>restart</on_reboot> <on_crash>destroy</on_crash> <devices> <emulator>/usr/bin/kvm</emulator> <disk type='file' device='cdrom'> <driver name='qemu' type='raw'/> <source file='/data/images/debian-live-6.0.4-amd64-standard.iso'/> <target dev='hdc' bus='ide'/> <readonly/> <alias name='ide0-1-0'/> <address type='drive' controller='0' bus='1' target='0' unit='0'/> </disk> <disk type='file' device='disk'> <driver name='qemu' type='qcow2'/> <source file='/data/domains/2f8baacd-563c-b747-b621-c0ddb4aa84bd'/> <target dev='vda' bus='virtio'/> <alias name='virtio-disk0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/> </disk> <controller type='usb' index='0'> <alias name='usb0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/> </controller> <controller type='ide' index='0'> <alias name='ide0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/> </controller> <interface type='bridge'> <mac address='52:54:00:39:86:29'/> <source bridge='br0'/> <target dev='vnet2'/> <model type='virtio'/> <alias name='net0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> </interface> <input type='tablet' bus='usb'> <alias name='input0'/> </input> <input type='mouse' bus='ps2'/> <graphics type='vnc' port='5902' autoport='yes'/> <video> <model type='vga' 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='0x04' function='0x0'/> </memballoon> </devices> <seclabel type='none'/> </domain> deb.xml: <disk type='file' device='cdrom'> <driver name='qemu' type='raw'/> <source file='/data/images/debian-live-6.0.4-amd64-standard.iso'/> <target dev='hdc' bus='ide'/> </disk> deb-off.xml: <disk type='file' device='cdrom'> <driver name='qemu' type='raw'/> <target dev='hdc' bus='ide'/> </disk> Thanks much, - Jasper

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[libvirt-users] R: Using libvirt to monitor virtual environment.
by robmail16＠libero.it 18 Oct '12

18 Oct '12

Hello I need a solution for monitoring and automatic migration of Guest vm machines. A good approach would be to determine which guests to migrate based on "trend usage algorithm". There is something in java and libvirt that could be used? RegardsRoberto ----Messaggio originale---- Da: vinicius.braga(a)lupa.inf.ufg.br Data: 18/10/2012 16.02 A: <libvirt-users(a)redhat.com> Ogg: [libvirt-users] Using libvirt to monitor virtual environment. Hey, I am new with libvirt. I am working to create a program to monitor a virtual environment. I have seen some solutions that use libvirt. Is this API good to make monitoring operations? I didn't see operations that show the CPU or memory usage, at least in Java binding. Are there operations like these, or we have to calculate based on lower level informations?

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[libvirt-users] 0.10.x incorrectly reporting currentMemory size
by Andrey Korolyov 18 Oct '12

18 Oct '12

Hi, <memory unit='KiB'>16777216</memory> <currentMemory unit='KiB'>1394380</currentMemory> <memtune> <hard_limit unit='KiB'>1594380</hard_limit> <soft_limit unit='KiB'>1494380</soft_limit> </memtune> results to: 0.10.x, .dominfo. or dumpxml | grep -i currentmemory Max memory: 16777216 KiB Used memory: 13977292 KiB 0.9.11-13: Max memory: 16777216 KiB Used memory: 1394380 KiB

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[libvirt-users] Migrating a LV backed guest
by Corey Quinn 18 Oct '12

18 Oct '12

I have a KVM VM that's backed by a logical volume on local disk. I'd like to copy / move it to an identically configured host. [root@virt2 cquinn]# virsh migrate --copy-storage-all --verbose --persistent node1.www qemu+ssh://10.102.1.11/system error: Unable to read from monitor: Connection reset by peer How should I effectively troubleshoot this? Am I misunderstanding how virsh migrate is supposed to work? Regards, Corey Quinn

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[libvirt-users] cgroup blkio.weight working, but not for KVM guests
by Ben Clay 17 Oct '12

17 Oct '12

I'm running libvirt 0.10.2 and qemu-kvm-1.2.0, both compiled from source, on CentOS 6. I've got a working blkio cgroup hierarchy which I'm attaching guests to using the following XML guest configs: VM1 (foreground): <cputune> <shares>2048</shares> </cputune> <blkiotune> <weight>1000</weight> </blkiotune> VM2 (background): <cputune> <shares>2</shares> </cputune> <blkiotune> <weight>100</weight> </blkiotune> I've tested write throughput on the host using cgexec and dd, demonstrating that libvirt has correctly set up the cgroups: cgexec -g blkio:libvirt/qemu/foreground time dd if=/dev/zero of=trash1.img oflag=direct bs=1M count=4096 & cgexec -g blkio:libvirt/qemu/background time dd if=/dev/zero of=trash2.img oflag=direct bs=1M count=4096 & Snap from iotop, showing an 8:1 ratio (should be 10:1, but 8:1 is acceptable): Total DISK READ: 0.00 B/s | Total DISK WRITE: 91.52 M/s TID PRIO USER DISK READ DISK WRITE SWAPIN IO> COMMAND 9602 be/4 root 0.00 B/s 10.71 M/s 0.00 % 98.54 % dd if=/dev/zero of=trash2.img oflag=direct bs=1M count=4096 9601 be/4 root 0.00 B/s 80.81 M/s 0.00 % 97.76 % dd if=/dev/zero of=trash1.img oflag=direct bs=1M count=4096 Further, checking the task list inside each cgroup shows the guest's main PID, plus those of the virtio kernel threads. It's hard to tell if all the virtio kernel threads are listed, but all the ones I've hunted down appear to be there. However, when running the same dd commands inside the guests, I get roughly-equal performance - nowhere near the ~8:1 relative bandwidth enforcement I get from the host: (background ctrl-c'd right after foreground finishes, both started within 1s of each other) [ben@foreground ~]$ dd if=/dev/zero of=trash1.img oflag=direct bs=1M count=4096 4096+0 records in 4096+0 records out 4294967296 bytes (4.3 GB) copied, 104.645 s, 41.0 MB/s [ben@background ~]$ dd if=/dev/zero of=trash2.img oflag=direct bs=1M count=4096 ^C4052+0 records in 4052+0 records out 4248829952 bytes (4.2 GB) copied, 106.318 s, 40.0 MB/s I thought based on this statement: "Currently, the Block I/O subsystem does not work for buffered write operations. It is primarily targeted at direct I/O, although it works for buffered read operations." from this page: https://access.redhat.com/knowledge/docs/en-US/Red_Hat_Enterprise_Linux/6/ht ml/Resource_Management_Guide/ch-Subsystems_and_Tunable_Parameters.html that this problem might be due to host-side buffering, but I have that explicitly disabled in my guest configs: <devices> <emulator>/usr/bin/qemu-kvm</emulator> <disk type="file" device="disk"> <driver name="qemu" type="raw" cache="none"/> <source file="/path/to/disk.img"/> <target dev="vda" bus="virtio"/> <alias name="virtio-disk0"/> <address type="pci" domain="0x0000" bus="0x00" slot="0x04" function="0x0"/> </disk> Here is the qemu line from ps, showing that it's clearly being passed through from the guest XML config: root 5110 20.8 4.3 4491352 349312 ? Sl 11:58 0:38 /usr/bin/qemu-kvm -name background -S -M pc-1.2 -enable-kvm -m 2048 -smp 2,sockets=2,cores=1,threads=1 -uuid ea632741-c7be-36ab-bd69-da3cbe505b38 -no-user-config -nodefaults -chardev socket,id=charmonitor,path=/var/lib/libvirt/qemu/background.monitor,server,n owait -mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc -no-shutdown -device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 -drive file=/path/to/disk.img,if=none,id=drive-virtio-disk0,format=raw,cache=none -device virtio-blk-pci,scsi=off,bus=pci.0,addr=0x4,drive=drive-virtio-disk0,id=virti o-disk0,bootindex=1 -netdev tap,fd=20,id=hostnet0,vhost=on,vhostfd=22 -device virtio-net-pci,netdev=hostnet0,id=net0,mac=00:11:22:33:44:55,bus=pci.0,addr= 0x3 -chardev pty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0 -device usb-tablet,id=input0 -vnc 127.0.0.1:1 -vga cirrus -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x5 For fun I tried a few different cache options to try to force a bypass the host buffercache, including writethough and directsync, but the number of virtio kernel threads appeared to explode (especially for directsync) and the throughput dropped quite low: ~50% of "none" for writethrough and ~5% for directsync. With cache=none, when I generate write loads inside the VMs, I do see growth in the host's buffer cache. Further, if I use non-direct I/O inside the VMs, and inflate the balloon (forcing the guest's buffer cache to flush), I don't see a corresponding drop in background throughput. Is it possible that the cache="none" directive is not being respected? Since cgroups is working for host-side processes I think my blkio subsystem is correctly set up (using cfq, group_isolation=1 etc). Maybe I miscompiled qemu, without some needed direct I/O support? Has anyone seen this before? Ben Clay rbclay(a)ncsu.edu

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