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[libvirt-users] share nothing live migration causes read only filesystem
by Fırat KÜÇÜK 17 Mar '16

17 Mar '16

Hello, I started live migration job for a guest with the following command: virsh migrate --live --domain my-guest --verbose --persistent --copy-storage-all --desturi qemu+ssh://root@my-otherhost/system Guest system disk cache mode is none: <disk type='file' device='disk'> <driver name='qemu' type='qcow2' cache='none'/> <source file='/opt/datastore/bulutkare-1118.img'/> <backingStore/> <target dev='vda' bus='virtio'/> <alias name='virtio-disk0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/> </disk> after live migration completed, filesystem blocked write operations. root@my-guest:~/tmp# touch hello touch: cannot touch ‘hello’: Read-only file system What can be the reason? What is the best of migrating a VM to a target machine? Additional info: Guest operating system is Ubuntu 14.04 x64 Source/Target Host operating system is Ubuntu 15.04 x64 Guest file system is ext4 + swap Source/Target Host file system is XFS Source/Target Qemu version 1.2.2 Source/Target libvirt 1.2.12 This is from target libvirt log. It can be important: /build/qemu-Bjjgxn/qemu-2.2+dfsg/nbd.c:nbd_co_receive_request():L1146: reading from socket failed

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[libvirt-users] disabling disk cache
by Fırat KÜÇÜK 17 Mar '16

17 Mar '16

Hello, is it possible to disable disk (vda) cache without rebooting system? Thanks.

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[libvirt-users] Re：Re: [help] How to modify the vgamem value ?
by hongzhen_luo＠sina.com 16 Mar '16

16 Mar '16

Dear Mr Holger and Mr Pavel Thanks for your help , I am going to try to modify the vgamem value . ^ ^Have a nice day ... Best regards >Hi Pavel, >I have to apologize. After your post I study the page again and I >found your descrption. >Best regards, >Am 14.03.2016 um 10:20 schrieb Pavel Hrdina: > On Mon, Mar 14, 2016 at 09:41:36AM +0100, Holger Schranz wrote: >> Hi Luo, >> >> the vgamem is limited inside. Myself, I use QEMU 2.5/Virgil3D to expand >> the vgamem. > > It's not limited and can be modified inside the xml, the only limitation is that > the value has to be a power of 2 and for QXL the value must be at least 1024. > There is an exception, qemu can and in some cases updates the value internally, > libvirt after the guest is started will get the actual value from qemu and > update live XML. > > Pavel >

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[libvirt-users] Unsupported network type ethernet using LXC
by abhishek jain 15 Mar '16

15 Mar '16

Hi Team I'm trying to launch VM using LXC as a hypervisor with interace="ethernet" configuration and I'm getting below errors.. *virsh -c lxc: start instance-00000321error: Failed to start domain instance-00000321error: internal error: Unsupported network type ethernet* Below is the xml file which I'm using .... cat right.xml <domain type='lxc'> <name>instance-00000321</name> <uuid>13dd822c-a99d-4f28-9f4e-53dfb744efcc</uuid> <memory unit='KiB'>524288</memory> <currentMemory unit='KiB'>524288</currentMemory> <vcpu placement='static'>1</vcpu> <resource> <partition>/machine</partition> </resource> <os> <type arch='aarch64' machine='virt'>exe</type> <init>/bin/sh</init> <cmdline>root=/dev/ram0 rw console=ttyAMA0 rootwait earlyprintk</cmdline> </os> <clock offset='utc'/> <on_poweroff>destroy</on_poweroff> <on_reboot>restart</on_reboot> <on_crash>destroy</on_crash> <devices> <emulator>/usr/lib/libvirt/libvirt_lxc</emulator> <filesystem type='mount' accessmode='passthrough'> <source dir='/'/> <target dir='/'/> </filesystem> <interface type='ethernet'> <mac address='02:74:ff:9d:52:f5'/> <script path=''/> <target dev='tap74ff9d52-f5'/> </interface> <interface type='ethernet'> <mac address='02:9b:a6:1e:67:5b'/> <script path=''/> <target dev='tap9ba61e67-5b'/> </interface> <console type='pty'> <target type='lxc' port='0'/> </console> </devices> <seclabel type='none'/> </domain> However I'm able to launch the same above xml file using KVM as hypervisor on the same host. Please help me regarding this. --Thanks Abhishek Jain

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[libvirt-users] TCP Tunnel Info
by bancfc＠openmailbox.org 14 Mar '16

14 Mar '16

libvirt-users(a)redhat.com TCP Tunnel Info I've been looking at the TCP Tunnel network feature as a potential replacement for the extra private internal networking configuration file. Usecase: This network is supposed to go from VM1 to VM2 without DHCP, DNS or any incoming/outgoing connections to the host or outside world possible. https://libvirt.org/formatdomain.html#elementsNICSTCP * To make sure I understand, adding the TCP Tunnel setting for both VMs 1 and 2 is enough to do what I need? (force them to exclusively communicate without the need for adding a new network as typically done). * If another set of VMs 3 and 4 are running and connected to each other but I want to make sure they cannot connect to VMs 1 and 2, what source addresses should be used to isolate these 2 networks? Do you follow CIDR rules? * For example if the chosen source address is 10.152.152.11 for VMs 1 and 2 what should the other network have? * Going more complicated. Can one VM participate in two separate TCP Tunnel networks while keeping them isolated? Topology: VM1(virtual NIC1) <-> VM2 | VM1(virtual NIC2) <-> VM3 VM2 and 3 can only talk to VM1 but not to each other in this example. * Offtopic: Do your answers similarly apply for using the other Multicast and UDP options too? I can explain better if I'm not making any sense.

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[libvirt-users] [help] How to modify the vgamem value ?
by hongzhen_luo＠sina.com 14 Mar '16

14 Mar '16

Dear everyone Do you know how to modify vgamem value in the .xml file ? such as :<video> <model type='qxl' ram='65536' vram='65536' vgamem='16384' heads='1'/> // from instance-0000015e.xml <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/</video> I plan to increase the volume of vgamem , but it seems that always keep the original value ‘16384’. Was it limited by QEMU? or others？ Please tell me how I can I modify it ? it's better that help me to make a example for modifing the vgamem..... Thank you very much Best Regards .

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[libvirt-users] Where are libvirt's USB autroredirection settings stored?
by bancfc＠openmailbox.org 12 Mar '16

12 Mar '16

For security reasons Debian's libvirt maintainer has opted to disable the default behavior of autoredirecting any newly attached USB device to a running VM with SPICE USB redirection ports added. I tried looking for an obvious setting in virt-manager's menus to change this but can't see anything. What libvirt/virt-manager configuration file is this setting stored so I can change it on demand?

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[libvirt-users] 100% CPU when using nested virtualization
by Digimer 11 Mar '16

11 Mar '16

Hi all, I got a new laptop recently and what worked before no longer works (Fedora 23 on the laptops in both cases)... I'm trying to get nested virtualization to work because I use the VMs on the laptop to simulate an HA cluster that itself hosts VMs. I don't care much at all about the performance of the nested VM, it's just there so that I can work on the cluster's code. When I try to provision a VM inside a VM (the host VM is CentOS/RHEL 6.7), the CPU load spikes to such a high degree that my ssh session times out after a while. The VM appears in libvirtd (as viewed by virt-manager on another machine), but the VM itself never starts. In one case, the VM host remained somewhat functional and killing kvm/qemu/libvirtd didn't reduce the CPU load. The main difference between the setups is that the older laptop had a Sandy bridge(? Thinkpad W530) and the new laptop is a Broadwell (Thinkpad P70). I've tried to loading vhost_net without much luck. I have, of course, enabled nesting on the actual hardware: cat /sys/module/kvm_intel/parameters/nested Y Any tips on how to debug? I'm in quite a pickle with this, so any and all help is much appreciated. -- Digimer Papers and Projects: https://alteeve.ca/w/ What if the cure for cancer is trapped in the mind of a person without access to education?

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[libvirt-users] EPT Misconfiguration
by Andrei Perietanu 10 Mar '16

10 Mar '16

I am using libvirt 1.2.20. I noticed that when running some VMs (CentOS ) with 2G ram, 2CPUs each for some reason they go from 'state=running' to 'state=paused'; and they can't be restarted. They are un-usable. When this happens I get the following in dmesg output: [ 46.595265] EPT: Misconfiguration. [ 46.595271] EPT: GPA: 0xfee000b0 [ 46.595275] ept_misconfig_inspect_spte: spte 0x7e4968107 level 4 [ 46.595279] ept_misconfig_inspect_spte: spte 0x7e4961107 level 3 [ 46.595281] ept_misconfig_inspect_spte: spte 0x7e4960107 level 2 [ 46.595284] ept_misconfig_inspect_spte: spte 0x7e592ff77 level 1 I have seen discussions about this topic, but for older code versions. The problem happens often and I could not find a fix for it. Has anyone seen this?Is there a fix for it? Thanks, Andrei -- The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of or taking of any action in reliance upon this information by persons or entities other than the intended recipient is prohibited. If you receive this in error please contact the sender and delete the material from any computer immediately. It is the policy of Klas Limited to disavow the sending of offensive material and should you consider that the material contained in the message is offensive you should contact the sender immediately and also your I.T. Manager. Klas Telecom Inc., a Virginia Corporation with offices at 1101 30th St. NW, Washington, DC 20007. Klas Limited (Company Number 163303) trading as Klas Telecom, an Irish Limited Liability Company, with its registered office at Fourth Floor, One Kilmainham Square, Inchicore Road, Kilmainham, Dublin 8, Ireland.

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[libvirt-users] Zombie processes being created when console buffer is full
by Peter Steele 10 Mar '16

10 Mar '16

We have been researching stuck zombie processes in our libvirt lxc containers. What we found was: 1) Each zombie’s parent was pid 1. init which symlinks to systemd. 2) In some cases, the zombies were launched by systemd, in others the zombie was inherited. 3) While the child is in the zombie state, the parent process (systemd) /proc/1/status shows no pending signals. 4) Attaching gdb to systemd, there was 1 thread and it was waiting in write() and the file being written was /dev/console. This write() to the console never returns. We operated under the assumption that systemd's SIGCHLD handler sets a bit and a foreground thread (the only thread) would see that child processes needed reaping. While the single thread is stuck in write(), the reaping never takes place. So why is write() blocking? The answer seems to be that there is nothing draining the console and eventually it blocks write() when its buffers become full. When we attached to the container's console, the buffer is cleared allowing systemd’s write() to return. The zombies are then reaped and everything goes back to normal. Our “solution” was more of a workaround. systemd was altered to log errors/warnings/etc to /dev/null instead of /dev/console. This prevented the problem, only in that the console buffer was unlikely to get filled up since systemd generally is the only then that writes to it. This is definitely a hack though. This may be a bug in the libvirt container library (you can't expect something to periodically connect to a container's console to empty it out). We suspect there may also be a configuration issue in our containers with regards to the console. Has anyone else observed this problem? Peter _______________________________________________ libvirt-users mailing list libvirt-users(a)redhat.com https://www.redhat.com/mailman/listinfo/libvirt-users

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