October 2013 - Users - libvirt List Archives

[libvirt-users] Bringing up a guest with network disabled
by James Gibbon 05 Oct '13

05 Oct '13

Hello all, I have a KVM guest VM which is a clone of a production machine running on a different physical server, incarnated from an image backup. I want to start up the clone, but obviously it has the same IP address at the moment, and naturally I want to avoid an IP conflict. Normally I'd mount the clone image, go in and change the network config to allocate a different IP, but because it's set up with its whole disk as a LVM that's a bit painful. Is there a simple way I can disable the networking for the guest clone in the config file, so I can VNC into its console and change its IP address config that way? The devices section of the config looks like this: <devices> <emulator>/usr/libexec/qemu-kvm</emulator> <disk type='file' device='disk'> <driver name='qemu' type='raw' cache='writeback'/> <source file='/var/lib/libvirt/images/sonic2.img'/> <target dev='hda' bus='ide'/> </disk> <interface type='bridge'> <mac address='0A:F7:B6:96:BF:85'/> <source bridge='br0'/> </interface> <serial type='pty'> <target port='0'/> </serial> <console type='pty'> <target port='0'/> </console> <input type='mouse' bus='ps2'/> <graphics type='vnc' port='5937' autoport='no' keymap='en-gb'/> </devices> .. can I change that 'interface type' value to disable its interface? Thanks, James

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[libvirt-users] Changing test_driver.c file
by Arun Viswanath 04 Oct '13

04 Oct '13

Hi All, For some testing purpose I've changed some content in src/test/test_driver.c and then used "make" command to compile and build the code. Then I copied the "libvirt.so.0.9.10.so" file to the target machine and restart the libvirtd daemon, but the changes I made in test_driver.c is nothing reflected. I'm not sure whether I'm missing something. Is it moving only the "libvirt.so.0.9.10.so" is enough or I need to move some .a files ? , but I'm not seeing any ".a" in the kvm host related to libvirt to replace. Please provide me sufficient info to proceed further. Thanks In Advance, Arun V

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[libvirt-users] Xen Project Developer Summit: check the schedule and register!
by Dario Faggioli 04 Oct '13

04 Oct '13

Hi all, The program for the Xen Project Developer Summit 2013 has been announced! Get more details at the links below: xendevelopersummit2013.sched.org/ http://blog.xen.org/index.php/2013/10/02/xen-project-developer-summit-line-… http://events.linuxfoundation.org/events/xen-project-developer-summit Don't miss the opportunity to come and see what's going on in the Xen Project's community. Register and join us in Edinburgh! Regards, Dario -- <<This happens because I choose it to happen!>> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK)

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[libvirt-users] passthrough shared dir with kvm: need to run as root?
by Raphael Bauduin 03 Oct '13

03 Oct '13

Hi, I need to mount a directory from the host in a guest, with passthough (ie, owner id and group set in the guest should be preserved and written on the host). I've read that for this to work, qemu needs to be run as root. Is there a way to start qemu as root via libvirt? Thanks raph

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[libvirt-users] Snapshots: Where they are stored and how to use them?
by Roland Giesler 02 Oct '13

02 Oct '13

Firstly I'd like to learn where a snapshot is stored once it has been made. I understand that the principle is that when changes occur in the VM, the difference is written to the snapshot, thus recording the differences between the date/time of the snapshot and the current value of the VM. Is that a correct assessment of the process? If that is indeed so, can I take regular snapshots and back then up onto external storage to provide a sort of system restore point at certain times in the past? I have scanned the server hard disks for the snapshot images after running "sudo virsh snapshot-create Windows /etc/libvirt/snapshot.xml" and the system reports a snapshot was taken, yet I cannot find any file that contains the snapshot. $ sudo virsh snapshot-list Windows Name Creation Time State ------------------------------------------------------------ Windows 2013-10-02 12:41:06 +0200 running What will happen to the snapshot if the host server is restarted? Some insight would be greatly appreciated. regards Roland

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[libvirt-users] Bridging Wireless Cards for KVM
by Joshua McKee 02 Oct '13

02 Oct '13

Hi, I hope this is the right place to ask this question. I was wondering if there is a way to set up a KVM VM using an XML document as input into Virsh that uses bridged networking over a wireless card. I understand that wireless cards to not natively support, but I was able to find a working solution here: http://blog.ericwhite.ca/articles/2011/04/creating-a-wireless-bridge/. The issue is, I can use this bridge by calling KVM directly. However, I cannot figure out how to get this same configuration on an XML file that I input into Virsh for the creation of a VM. My understanding is that libvirt calls KVM/QEMU at some point, but I may be mistaken. Thanks, Joshua

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[libvirt-users] Accessing the host server's file system from a guest OS
by Roland Giesler 02 Oct '13

02 Oct '13

Is there no way in which one can access the host's filesystem from within a guest OS. Libvirt's virt-manager GUI seems to indicate that there is, by virtue of the FileSystem Passthrough option as shown below [image: Inline image 1] The scenario I typically have is a Linux Server on a ext4 file system, with a Windows 7 Guest OS running a KVM machine. No matter what combination of options I choose, I can never "mount" the host drive in Windows to be able to transfer files from one to the other. Both VMWare Player and Virtualbox have this capability, yet I find this sorely lacking in libvirt/virt-manager. What do I need to do to make this work? regards Roland

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[libvirt-users] libvirt installtion.
by cooldharma06 01 Oct '13

01 Oct '13

hi, i am facing some error i am not able to find how to solve this. i just explain my whole things. i installed libvirt 1.1.2 from source under /opt/ folder. ./configure --with-xen=yes, make , make install. i faced some internal error so runned make clean , make distclean under libvirt source folder. then agian i tried to install libvirt 1.1.2 ./configure --prefix=/usr --localstatedir=/var --sysconfdir=/etc --with-xen=yes --with-libxl=yes make make install. i faced some error. i mailed those error in my previous mail. then i cleared (removed by make clean) the libvirt 1.1.2 and i tried to install the libvirt 1.1.1 with the following commands: ./configure --prefix=/usr --localstatedir=/var --sysconfdir=/etc --with-xen=yes make make install i am getting the below error. root(a)boss[libvirt-1.1.1]#libvirtd -v libvirtd: /usr/local/lib/libvirt.so.0: version `LIBVIRT_PRIVATE_1.1.1' not found (required by libvirtd) give me some solution to solve the above error.. regards, cooldharma06.

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[libvirt-users] LXC, libvrt-1.1.2-r3 (Gentoo), "/dev/tty12", mount /dev with inverse of 'nodev'?
by Dennis Jenkins 01 Oct '13

01 Oct '13

Hello again, TL;DR: Today I noticed that my LXC container was out of space in "/dev". It took me a few minutes to figure out why. There were only 23 files there. The "/dev" fs quota was 64K, and all was taken up. The problem was that "syslog-ng" was writing "console" messages to "/dev/tty12". But "/dev/tty12" was not a device node, so the kernel "(2)open"ed it as a file and dutifully wrote to it. I have corrected my syslog-ng config, but I was wondering.... Is there any legitimate reason to EVER have a regular file in "/dev"? If not, can libvirt or Linux be modified so that the filesystem can be mounted in such a way to prevent a regular file from ever being created there? Kind of like an inverse of the "nodev" mount option seen in various filesystems (ext3, nfs). IMHO, I would rather have syslog-ng (or other tool) fail to open a regular file in "/dev", than for it is succeed and then fill up the small fs. Thoughts? Boring stuff: Sep 30 14:06:47 localhost syslog-ng[440]: Error suspend timeout has elapsed, attempting to write again; fd='16' Sep 30 14:06:47 localhost syslog-ng[440]: I/O error occurred while writing; fd='16', error='No space left on device (28)' Sep 30 14:06:47 localhost syslog-ng[440]: Suspending write operation because of an I/O error; fd='16', time_reopen='60' This is what I see inside the container: djenkins@dwj-hfax-dev ~/src/HylaFAX+ $ find /dev | wc -l 23 dwj-hfax-dev ~ # ls -l /dev/tty* crw-rw-rw- 1 root root 5, 0 Sep 30 13:44 /dev/tty lrwxrwxrwx 1 root root 10 Sep 30 13:03 /dev/tty1 -> /dev/pts/0 -rw------- 1 root root 65536 Sep 30 14:12 /dev/tty12 ### AHHH!!! There is the problem. "syslog-ng" is writing to "/dev/tty12", but it is a file and not a real device. djenkins@dwj-hfax-dev ~/src/HylaFAX+ $ du -sh /dev 64K /dev djenkins@dwj-hfax-dev ~/src/HylaFAX+ $ df -h /dev Filesystem Size Used Avail Use% Mounted on devfs 64K 64K 0 100% /dev

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