December 2010 - Users - libvirt List Archives

[libvirt-users] Problems Installing KVM Guest + Console Access
by tony＠specialistdevelopment.com 20 Dec '10

20 Dec '10

Hi, Im having real issues with getting a kvm guest up and running on CentOS 5.5 I have expanded the iso to a path on my system as I have been told that the -x (extra arguments) will not work with the -cdrom option, so I am now using -location, but still the extra arguments are not being picked up. So what do I need to do to get a guest up and working with console access to view the install as its driving me crazy. Thanks Tony

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[libvirt-users] pool info is not updated until pool refresh is run.
by Sharad Mishra 17 Dec '10

17 Dec '10

Hi, Creating a volume does not update pool information until pool-refresh is run. Here is an example - # virsh vol-create ShareStorage /tmp/vol.xml Vol sm_disk.dsk created from /tmp/vol.xml # virsh pool-info ShareStorage Name: ShareStorage UUID: 3ab7dbd5 State: running Capacity: 58.57 GB Allocation: 4.91 GB Available: 53.66 GB # virsh vol-info /var/lib/libvirt/test/sm_disk.dsk Name: sm_disk.dsk Type: file Capacity: 97.66 GB Allocation: 95.47 MB # virsh pool-refresh ShareStorage Pool ShareStorage refreshed # virsh pool-info ShareStorage Name: ShareStorage UUID: 3ab7dbd5 State: running Capacity: 58.57 GB Allocation: 5.01 GB Available: 53.57 GB Why pool-refresh is required to update pool-info? Thanks, Sharad Mishra

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[libvirt-users] aio flag for KVM guests
by Rangababu Chakravarthula 17 Dec '10

17 Dec '10

Hello, We are using libvirt 0.8.3 to build KVM guests (KVM version is qemu-kvm 0.12.5). I see kvm supports aio flag with either native or threads option. Where in libvirt XML should we define aio option? Thanks in advance Ranga

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[libvirt-users] busy loop in libvirtd (cpu usage 100%)
by Igor Serebryany 16 Dec '10

16 Dec '10

Hi! Occasionally of late, I've seen a few cases where libvirtd cpu usage shoots up to 100% and stays there indefinitely. This seems to happen when a QEMU VM is starting up, although on one occasion I *think* I saw it happen after a QEMU VM was p2p-migrated. Doing strace -f -p <libvirtd pid> reveals a flood of poll() functions calls like these: [pid 1690] poll([{fd=3, events=POLLIN}, {fd=6, events=POLLIN}, {fd=12, events=POLLIN|POLLERR|POLLHUP}, {fd=11, events=POLLIN|POLLERR|POLLHUP}, {fd=10, events=POLLIN|POLLERR|POLLHUP}, {fd=9, events=POLLIN|POLLERR|POLLHUP}, {fd=24, events=POLLIN|POLLERR|POLLHUP}, {fd=21, events=POLLOUT}, {fd=14, events=POLLIN}, {fd=15, events=POLLIN}, {fd=16, events=POLLIN}, {fd=17, events=POLLIN}, {fd=21, events=POLLIN|POLLERR|POLLHUP}, {fd=20, events=POLLIN|POLLERR|POLLHUP}], 14, -1) = 1 ([{fd=21, revents=POLLOUT}]) It seems that because 1 is returned each time, libvirtd just goes crazy dealing with fd-3, but I have no idea what fd-3 is. Restarting libvirtd fixes the high load, and then everything just goes back to chugging along as usual. This is on libvirt 0.8.5 with qemu 0.12.5 on a debian Squeeze system (the libvirt is compiled by hand). I'm not sure what's causing it, whether it's a bug in my own code somehow or inside libvirtd. I'd appreciate some help on how to debug this problem further -- restarting libvirtd is kind of a pain for me, because my application, which monitors the health on the node, maintains open connections to 'qemu:///system' and would thus have to restart itself as well... --Igor

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[libvirt-users] KVM Virtualisation, Console output no longer working
by tony＠specialistdevelopment.com 15 Dec '10

15 Dec '10

Hi, I used to use KVM for virtualisation and have now moved back to it, but I have a problem. When i used to install the guest machine with virt-install i used to use the -x "extra args" part to set the console for the install and guest, but it no longer works. Here is the command i use: virt-install -n server01 -r 512 --os-variant=virtio26 -c /isos/c5u5.iso --nographics --noautoconsole -f /storage/vm/server01 -s 5 bus=virtio -w bridge:br0 -x "console=ttyS0 ks=http://www.domain.com/c5u5.cfg" As you can see im setting the console to ttyS0, but then when i go to connect to the console with: virsh console server01 it either wont connect or comes up with: error: Failed to get local hostname Here is a dump of the xml, but no mention of ttyS0 either. <domain type='qemu' id='5'> <name>server01</name> <uuid>5991cf85-db6c-2b87-b76d-07a0caae77b9</uuid> <memory>524288</memory> <currentMemory>524288</currentMemory> <vcpu>1</vcpu> <os> <type arch='x86_64' machine='rhel5.4.0'>hvm</type> <boot dev='cdrom'/> </os> <features> <acpi/> <apic/> <pae/> </features> <clock offset='utc'/> <on_poweroff>destroy</on_poweroff> <on_reboot>destroy</on_reboot> <on_crash>destroy</on_crash> <devices> <emulator>/usr/libexec/qemu-kvm</emulator> <disk type='file' device='disk'> <driver name='qemu' cache='none'/> <source file='/storage/vm/server01'/> <target dev='hda' bus='ide'/> </disk> <disk type='file' device='cdrom'> <source file='/isos/c5u5.iso'/> <target dev='hdc' bus='ide'/> <readonly/> </disk> <interface type='bridge'> <mac address='54:52:00:61:ea:78'/> <source bridge='br0'/> <target dev='vnet0'/> </interface> <serial type='pty'> <source path='/dev/pts/2'/> <target port='0'/> </serial> <console type='pty' tty='/dev/pts/2'> <source path='/dev/pts/2'/> <target port='0'/> </console> </devices> </domain> Can anyone shed any light on this as im totally stuck.

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[libvirt-users] Deploying libvirt with live migration
by Scott Baker 13 Dec '10

13 Dec '10

I have two physical servers: Virt1 and Virt2. I'm setting up live migration with CentOS 5.5 between the two. I've done this by NFS mounting /etc/libvirt and /var/lib/libvirt/images on both servers. This is working well for me except for one thing. I see the same list of VMs on each server (as expected), but each server (Virt1 and Virt2) are able to start the same VM at the same time. This obviously causes IP conflicts and thrashes the disk image. Is there a way to tell my VM "cluster" that a VM is only allowed to be opened on one host at a time? -- Scott Baker - Canby Telcom System Administrator - RHCE - 503.266.8253

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[libvirt-users] Best filesystem/nfs options for shared storage?
by Scott Baker 13 Dec '10

13 Dec '10

Is there a guide, or some suggestions for what filesystem to use for VM storage? I chose the standard ext3 on CentOS but I'm wondering if it makes more sense to look at ext4 or XFS for performance reasons? Does anyone tweak the ext3 journaling options for libvirt to speed things up? What about NFS export/mount options? What do your fstab mount lines look like? Is there a better rsize/wsize than the default? -- Scott Baker - Canby Telcom System Administrator - RHCE - 503.266.8253

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[libvirt-users] libvirt printing to stderr
by Albert Hopkins 13 Dec '10

13 Dec '10

I'm writing an app and using the Python bindings for libvirt. Everything is fine but, in some cases I need to call lookupByName(). There are a lot of times when the name will not exist, I trap the exception, however I still get this message printed to stderr: libvir: QEMU error : Domain not found: no domain with matching name 'foo' Is there any way to turn this off? This is a command-line program so the extra output makes the interface confusing. I've tried re-assigning sys.stderr before calling lookupByName(), but that doesn't seem to have any affect. tia, -albert

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[libvirt-users] LXC Live Migration possible?
by Dan Lüdtke 13 Dec '10

13 Dec '10

Hallo everyone, in March 2010 there was a discussion[1] about live migration of LXC Containers using libvirt. I was just wondering if there are any updates to this? regards, Dan Luedtke [1] http://www.mail-archive.com/lxc-users@lists.sourceforge.net/msg00198.html -- https://www.danrl.de/ GPG Key ID: 0xF8504F3E

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[libvirt-users] ANNOUNCE: ruby-libvirt bindings 0.3.0
by Chris Lalancette 13 Dec '10

13 Dec '10

All, I'm pleased to announce the release of 0.3.0 of the ruby-libvirt bindings. This release has a number of updates: * Implementation of Libvirt::open_auth, Libvirt::event_register_impl * Updated Connect class, implementing conn.compare_cpu, conn.baseline_cpu, conn.domain_event_register_any, conn.domain_event_deregister_any, conn.domain_event_register, conn.domain_event_deregister, and conn.create_domain_xml. * Updated Domain class, implementing dom.get_vcpus, dom.update_device, dom.scheduler_type, dom.scheduler_parameters, dom.scheduler_parameters=, dom.num_vcpus, dom.vcpus_flags=, and dom.qemu_monitor_command. * Updated Interface class, implementing interface.free * Many potential memory leaks have been fixed. * Many bugfixes. * Documentation update of many methods, including all of the lookup methods that were missing before. With the above list, almost all of the APIs up to and including libvirt 0.8.6 are covered. There are a few that I have not yet had time to implement; you can look at the list in the README file in the source tree to see which ones are missing. The tarballs and source RPMs are here: http://libvirt.org/ruby/download/ The git repository is here: http://libvirt.org/git/?p=ruby-libvirt.git;a=summary The documentation for all of the APIs are here: http://libvirt.org/ruby/api/index.html I've uploaded some examples on how to use the bindings: http://libvirt.org/ruby/documentation.html I've also pushed a new gem to rubygems.org; you should be able to use 'gem install ruby-libvirt' (if you haven't installed them before) or 'gem update ruby-libvirt' (if you have them installed already). If you have time, and are interested in the bindings, please give these new ones a whirl and let me know if they work for you. Note that release 0.3.0 is intended to be fully backwards compatible with release 0.2.0 and 0.1.0. If you find that they are not, or find any other problems with the ruby bindings, please report it to the libvirt development mailing list (and CC me) so that I can take a look at them. Thanks, -- Chris Lalancette

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