June 2016 - Users - libvirt List Archives

[libvirt-users] Need information
by Gk Gk 20 Jun '16

20 Jun '16

Hi, I am referring to the 'Routed Mode' section just under the section 'Other virtual network switch routing types' in the URL ' http://wiki.libvirt.org/page/VirtualNetworking#Routed_mode'. In the above link, for routed mode, it is stated that 'In this mode all virtual machines are in a subnet routed through the virtual switch.' Can anyone explain to me, if the guest machines have to be in the same subnet as the Host machine for the routed mode to work (o)r can the guest machines be in any subnet different from the host machine in routed mode ? Thanks Kumar

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[libvirt-users] libvirt can't communicate over network while creating VM
by Mensik, Petr 16 Jun '16

16 Jun '16

Hello guys, we use libvirt for dynamic creation of our VM and we do various modifications of those VMs in the process. One with I am struggling with is to signing keys of our custom repository - " vm.sh("wget -O - " + key_address + " | apt-key add -")" where "vm" is a GuestFS object. So I have set "vm.set_network(True)" and I have installed "dhcpcd5" package (that's whats on Debian Jessie) on both Host OS with KVM running and VM template (because we always copy Debian template we have in order to create new VM). However according to the log libvirt is still complaining that dhcpcd is missing (line 371 in the log). I ran dhcpcd command on both machines and I've even restarted networking service - unfortunately nothing helps. So I'd like to ask you for help or at least any hints. Thanks a lot. http://pastebin.com/d6zZG1BK P.S. I already wrote to the #libvirt channel on IRC but nobody replied so I am trying my luck here :) Best regards Petr Mensík

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[libvirt-users] CPU reservation.
by Dominique Ramaekers 14 Jun '16

14 Jun '16

Hi, I'd like some opinions regarding the configuration of my guest cpu. I had a physical server with a MSSQL on it. The license of the SQL server was of type 1 processor. This means, only one processor will be used by the SQL server. Recently I had virtualised this server on a 2 processor host. Correct me if I'm wrong, but now I can fool the SQL server by configuring one processors with a lot of cores and threats which results in using more than one physical processor. With a trick like this, I'm not running the server according to the license. To be on the safe side license-wise, I would like to configure my guest that it has only one physical processor at disposal and that this processor is reserved especially for this host. So, the other guests can't use that processor. There is the option cpu passtrough, but I think this will give me trouble when I migrate the guest to another host... There are a lot of possibilities configuring the cpu. What would be the best aproche? Thanks in advance. Dominique.

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[libvirt-users] libvirt-clone - Slow image cloning on a Server
by Philip Banh 14 Jun '16

14 Jun '16

Hello there, I have libvirt/kvm installed on a HP DL380 server and it seems to be cloning a template image very slowly, in fact a 50GB image just doesn't gets stuck after 7%. Is there a reason why this might be happening? I've tried the same setup on a desktop and never had this issue. The command and setup is listed below: virt-clone -o template.img -n new-clone -f .../new-clone.img System - 12 cores, 32 GB of memory - Running CentOS 7 - XFS file system using LVM - Libvirt 1.2.17 Thanks, Philip

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[libvirt-users] Host loses network connectivity when starting containers
by Peter Steele 14 Jun '16

14 Jun '16

I have hit a problem running libvirt based containers in a CentOS 7 based host, with the extra wrinkle that my host is an EC2 instance in AWS. Ultimately everything works as advertised, and I can launch instances that host multiple libvirt lxc containers without problems, with one caveat: About one time in ten when the containers are started, the instance loses all network connectivity. This can even happen on instances that host only a single container, so it's not related to the number of containers that are being run. Once this happens, the only way to fix the problem is to reboot the instance and hope that on the reboot, the containers will start successfully this time. In troubleshooting efforts that I've done I've found that the problem does not occur with containers defined with the linuxcontainers.org flavor of lxc. I've also discovered that if I configure my containers to use libvirt's default isolated bridge device virbr0, this loss of network connectivity does not appear to happen when the containers are started. Specifically, I ran a test that repeatedly started/stopped a single container configured with virbr0 and the test ran for a long time without an issue. When I switched the container to use my fully configured bridge device br0, the start/stop test usually hung up within a few iterations. Meaning that my ssh session into the instance would hang and I'd be unable to reconnect to the instance. Unfortunately AWS does not provide an console back door into an instance so troubleshooting has been difficult. I've checked the system logs though after one of these hangs occurs and there are no errors reported anywhere that I can see. I do not see this problem when running on real hardware. I also do not see the problem when running under other virtual environments, including VMware, KVM, and VirtualBox. My guess is that it is a bug in libvirt (since containers defined with the linuxcontainers.org lxc framework do not cause this issue.) There seems to be an AWS component to the problem as well though since I've only seen this happen in EC2 based instances. Is anyone familiar with this problem? Does anyone have any suggestions how I might resolve it? Note that I have tried a recent version of libvirt (1.3.2-1) and it behaves the same as the stock CentOS version of libvirt (1.2.17-13). Peter

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[libvirt-users] Reg. Libvirt packages with ver 1.2.12
by Das Pratik1 14 Jun '16

14 Jun '16

Hi, I am looking for deb packages of libvirt with version 1.2.12. It would be a great help if you can help me here. The following packages are in need : 1. libvirt-daemon-system (1.2.12) 2. libvirt-clients (1.2.12) 3. libvirt-daemon (1.2.12) If this is not the right place to contact, please redirect me to correct mailing group. Any help would be highly appreciated ! Thanks in advance ! Best Regards Pratik Das =====-----=====-----===== Notice: The information contained in this e-mail message and/or attachments to it may contain confidential or privileged information. If you are not the intended recipient, any dissemination, use, review, distribution, printing or copying of the information contained in this e-mail message and/or attachments to it are strictly prohibited. If you have received this communication in error, please notify us by reply e-mail or telephone and immediately and permanently delete the message and any attachments. Thank you

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[libvirt-users] RHEL 7.x Guests Unable to Detect Any Storage Disks
by James Stanley 13 Jun '16

13 Jun '16

Greetings, I have been troubleshooting an issue in my RHEL 7.x guests the last few days where I am unable to get any attached storage volumes detected. I've tried various formats (raw, qed, qcow2) as well as some different cache settings but I've not had any luck getting the guests to see the disks. Are you aware of any bugs around this? We've had problems with RHEL 7.x in other virtualization environments mostly due to networking problems, but I've never encountered a situation where storage doesn't show up under /dev or /dev/disk/by-*. For reference, here's an example volume entry in the domain's xml: <disk type='file' device='disk'> <driver name='qemu' type='raw'/> <source file='/image-mnt/storage/vol0'/> <target dev='sda' bus='scsi'/> <shareable/> <serial>12536725</serial> <address type='drive' controller='0' bus='0' target='0' unit='0'/> </disk> And here's how the volume is defined: <volume type='file'> <name>vol0</name> <key>/image-mnt/storage/vol0</key> <source> </source> <capacity unit='bytes'>24696061952</capacity> <allocation unit='bytes'>24696066048</allocation> <target> <path>/image-mnt/storage/vol0</path> <format type='raw'/> <permissions> <mode>0600</mode> <owner>187</owner> <group>474</group> </permissions> <timestamps> <atime>1465847232.644199995</atime> <mtime>1465846963.996202455</mtime> <ctime>1465846963.996202455</ctime> </timestamps> </target> </volume> Thanks for your help. Regards, James Stanley

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[libvirt-users] vhba and storage pool creation
by Johan Kragsterman 12 Jun '16

12 Jun '16

Hi! Got a couple of storage questions here. I'm a storage guy, running a new project, and just started with libvirt, but have been using qemu/kvm on other platforms before, as well as oVirt. So, my questions here: I started with creating a vhba, and that went fine, I could see it on the storage side logging in to the target with its wwn. My next step would be to make it persistent, and then its this storage pool creation I've seen. Though some things are not clear to me. This is what the xml file looks like in the documentation: <pool type='scsi'> <name>poolvhba0</name> <source> <adapter type='fc_host' wwnn='20000000c9831b4b' wwpn='10000000c9831b4b'/> </source> <target> <path>/dev/disk/by-path</path> <permissions> <mode>0700</mode> <owner>0</owner> <group>0</group> </permissions> </target> </pool> So there are a few of these things that are unclear to me: * It seems like I should NOT configure a vhba in advance, but this is the process that will configure the vhba for me? * It also seems like the wwnn and wwpn set here are the ones that the vhba will use, not the parent hba? * There is an option of setting the parent here as well, which I will need for some resons, but it is unclear to me whether the wwnn and wwpn's are from the parent or the vhba? Looks like this in documentation: <source> <adapter type='fc_host' parent='scsi_host5' wwnn='20000000c9831b4b' wwpn='10000000c9831b4b'/> </source> * So, are these wwpn and wwnn's from parent or vhba? * Lastly, the path: In the xml file it says /dev/disk/by-path...but I have no path...? Since I have not yet configured the vhba, I can not have a path? I can not map a lun to the vhba before I have a vhba... Or should I create a non persistent vhba, map a lun to it, and then source that path, use the wwpn and wwnn from that vhba in the scsi pool creation??? That would make sense, but also be a bit complicated to use... Best regards from/Med vänliga hälsningar från Johan Kragsterman Capvert

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[libvirt-users] How to use PHP libvirt_connect?
by Phill Edwards 12 Jun '16

12 Jun '16

I'm having a go at writing some PHP scripts to do simple things like view the status of VMs running on my Ubuntu KVM host. I've installed php_libvirt_php but am failing at the first hurdle at the moment as I can't get the PHP script to connect. My normal way of connecting virsh from the command line is like this: $ virsh -c qemu+ssh://localhost/system This asks for a password which is fine as I'm doing it from the command line. I can't get a connection when I use other protocols: $ virsh -c qemu+tcp://192.168.0.103/system error: failed to connect to the hypervisor error: unable to connect to server at '192.168.0.103:16509': Connection refused I've tried using various $uri values for libvirt_connect but I get connection errors: $uri="qemu+tcp://localhost/system"; Connecting to libvirt (URI:qemu+tcp://localhost/system) *Warning*: libvirt_connect(): unable to connect to server at 'localhost:16509': Connection refused in */var/www/html/libvirt_test1.php* on line *8* Libvirt last error: unable to connect to server at 'localhost:16509': Connection refused $uri="qemu://localhost/system"; Connecting to libvirt (URI:qemu://localhost/system) *Warning*: libvirt_connect(): Cannot read CA certificate '/etc/pki/CA/cacert.pem': No such file or directory in */var/www/html/libvirt_test1.php* on line *8* Libvirt last error: Cannot read CA certificate '/etc/pki/CA/cacert.pem': No such file or directory $uri="qemu+tcp://localhost/system"; Connecting to libvirt (URI:qemu+tcp://localhost/system) *Warning*: libvirt_connect(): unable to connect to server at 'localhost:16509': Connection refused in */var/www/html/libvirt_test1.php* on line *8* Libvirt last error: unable to connect to server at 'localhost:16509': Connection refused Presumably the answer is to 1) either allow connections that don't require SSH, or 2) somehow allow a password-less SSH connection from the www-data user that's running the PHP script. 2) sounds like it might be very difficult, and I don't know how to do 1) as I've only ever connected this way with SSH. Can anyone please provide some advise on getting this working.

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[libvirt-users] Prevent guest to host CPU overloads
by Joan Aymà 09 Jun '16

09 Jun '16

Hello, I have a domain on a host that makes it to get on a overload, i.g. host stops responding. The host is a Fedora 22 with follow packages: QEMU emulator version 2.3.0 libvirtd (libvirt) 1.2.13.1 VM is a MS Windows environment... I followed some info on libvirtd wiki but cannot get the idea to limit guest resources into libvirt or get guest limits to enforce host has priority. Must iothread and iops limits be sufficient? I attach some domain info. Thanks in advance.

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