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[libvirt-users] Sometimes libvirt fails to update domain block file after blockcommit.
by Matthew Schumacher 29 Apr '15

29 Apr '15

Posted to https://bugzilla.redhat.com/show_bug.cgi?id=1217185 I just stumbled on another bug while snapshotting and think it's related to 1210903 and 1197592 as it seems like some sort of race condition because it depends on what logging is in place and doesn't happen every time. Here are the details: I wrote this test script to snapshot and commit over and over: #!/bin/sh while [ 1 ]; do echo "Starting snapshot test `date`" virsh snapshot-create-as test 20150429 20150429-backup --disk-only --atomic virsh domblklist test virsh blockcommit test vda --active --pivot --verbose virsh snapshot-delete test 20150429 --metadata virsh domblklist test rm /glustervol1/vm/test/test.20150429 echo "Ending snapshot test `date`" echo echo sleep 2 done If I run libvirtd in the foreground with debug set to 1 I can't get it to fail, it does what it's supposed to do, snapshot and commit over and over. If I run libvirtd in the foreground with debug set to 3, then I will always eventually get this: Starting snapshot test Wed Apr 29 09:34:34 AKDT 2015 Domain snapshot 20150429 created Target Source ------------------------------------------------ vda /glustervol1/vm/test/test.20150429 hdc /dev/sr0 Block Commit: [100 %] Successfully pivoted Domain snapshot 20150429 deleted Target Source ------------------------------------------------ vda /glustervol1/vm/test/test.20150429 hdc /dev/sr0 Ending snapshot test Wed Apr 29 09:34:35 AKDT 2015 Starting snapshot test Wed Apr 29 09:34:37 AKDT 2015 error: unsupported configuration: source for disk 'vda' is not a regular file; refusing to generate external snapshot name Target Source ------------------------------------------------ vda /glustervol1/vm/test/test.20150429 hdc /dev/sr0 error: internal error: qemu block name '/glustervol1/vm/test/test.qcow2' doesn't match expected '/glustervol1/vm/test/test.20150429' error: Domain snapshot not found: no domain snapshot with matching name '20150429' Target Source ------------------------------------------------ vda /glustervol1/vm/test/test.20150429 hdc /dev/sr0 rm: can't remove '/glustervol1/vm/test/test.20150429': No such file or directory Ending snapshot test Wed Apr 29 09:34:37 AKDT 2015 At this point libvirt is confused about which file is the backing store because the first run did pivot after blockcommit, but didn't update the block file. From the logs: 2015-04-29 17:33:41.052+0000: 25192: warning : qemuDomainObjTaint:1972 : Domain id=2 name='test' uuid=4b9cc25b-68d1-4ce8-8a65-2a378e255e36 is tainted: high-privileges 2015-04-29 17:34:37.322+0000: 25191: error : virDomainSnapshotAlignDisks:609 : unsupported configuration: source for disk 'vda' is not a regular file; refusing to generate external snapshot name 2015-04-29 17:34:37.352+0000: 25194: error : qemuMonitorJSONDiskNameLookup:3977 : internal error: unable to find backing name for device drive-virtio-disk0 2015-04-29 17:34:37.354+0000: 25194: error : qemuMonitorJSONDiskNameLookupOne:3914 : internal error: qemu block name '/glustervol1/vm/test/test.qcow2' doesn't match expected '/glustervol1/vm/test/test.20150429' So libvirt insists that the block file is: root@wasvirt2:/glustervol1/vm/waspbx# virsh domblklist test Target Source ------------------------------------------------ vda /glustervol1/vm/test/test.20150429 hdc /dev/sr0 But that file isn't in use and isn't what qemu is using: root@wasvirt2:/glustervol1/vm/waspbx# lsof | grep test 25300 /usr/bin/qemu-system-x86_64 /var/log/libvirt/qemu/test.log 25300 /usr/bin/qemu-system-x86_64 /var/log/libvirt/qemu/test.log 25300 /usr/bin/qemu-system-x86_64 /glustervol1/vm/test/test.qcow2 The only way to straighten this out is to destroy and start the domain.

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[libvirt-users] non failover equivalent to "virsh migrate --copy-storage-all"
by Andreas Buschmann 29 Apr '15

29 Apr '15

Hello, I have two servers where I can push VMs from one to the other by issuing the command virsh migrate --live --persistent --copy-storage-all --verbose \ test6 qemu+ssh://kvmhost2/system on kvmhost1. I can get the VM back by issuing the equivalent command on kvmhost2: virsh migrate --live --persistent --copy-storage-all --verbose \ test6 qemu+ssh://kvmhost1/system virsh copies the local data file /data/vm/test6.qcow2 with the filesystem over to the other server. Is there a way to just copy the data file over to the second server, without moving the VM? I want the equivalent of doing these two migrations is sequence, but without moving the VM. The goal is to get a backup copy of a running system onto a second system (kvmhost2). The copy (snapshot) from kvmhost2 can then be copied to a backup server, and can be used for a fast recovery point if kvmhost1 dies. Mit freundlichen Gruessen Andreas Buschmann -- Andreas Buschmann [Senior Systems Engineer] net.DE AG

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[libvirt-users] Semantics of "virsh migrate --copy-storage-all" vs. --copy-storage-inc
by Andreas Buschmann 29 Apr '15

29 Apr '15

Hello, what is really the difference between virsh migrate --copy-storage-all and virsh migrate --copy-storage-inc ? There are some documents talking about NBD snapshots, but the user visible semantics are incomplete. Where does the incremental stuff happen? Does it require qcow2 files? Does it work with raw files? Does "--copy-storage-inc" require existing snapshots? Does "--copy-storage-inc" require existing snapshots which are in an external file so that there is a visible chain [base] <- [sn1] <- [sn2] Background: I am trying to understand what really happens, so I can use the tools for a reasonable fast failover between two servers with local storage. more Background: I have VMs and bare metal servers which do use expensive shared storages like NetApp, EMC² VNX, HP and others, but the shared storage boxes all require customer visible maintenance downtimes every 12 to 20 month. And these downtimes take a long lead time and are between 01:00 and 05:00. Mit freundlichen Gruessen Andreas Buschmann -- Andreas Buschmann [Senior Systems Engineer] net.DE AG

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[libvirt-users] Virtual Smartcard GPG
by roky＠openmailbox.org 29 Apr '15

29 Apr '15

Hi. Is is possible to use GPG on the host instead of NSS with virtual smartcards? Please document how or add support for it. Can a virtual smartcard make the host less secure? If there are bugs in GPG/NSS backend on the host can they be abused by untrusted code in the vm?

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[libvirt-users] Disable weak ciphers in vnc_tls
by Matthias Fenner 29 Apr '15

29 Apr '15

Dear libvirt team, we a currently in a pci-dss certification process and our security scanner found weak ciphers in the vlc_tls service on our centos6 box: When I scan using sslscan I can see that sslv3 and rc4 is accepted: inf0rmix@tardis:~$ sslscan myhost:16514 | grep Accepted Accepted SSLv3 256 bits DHE-RSA-AES256-SHA Accepted SSLv3 256 bits AES256-SHA Accepted SSLv3 128 bits DHE-RSA-AES128-SHA Accepted SSLv3 128 bits AES128-SHA Accepted SSLv3 128 bits RC4-SHA Accepted SSLv3 128 bits RC4-MD5 Accepted SSLv3 112 bits EDH-RSA-DES-CBC3-SHA Accepted SSLv3 112 bits DES-CBC3-SHA Accepted TLSv1 256 bits DHE-RSA-AES256-SHA Accepted TLSv1 256 bits DHE-RSA-CAMELLIA256-SHA Accepted TLSv1 256 bits AES256-SHA Accepted TLSv1 256 bits CAMELLIA256-SHA Accepted TLSv1 128 bits DHE-RSA-AES128-SHA Accepted TLSv1 128 bits DHE-RSA-CAMELLIA128-SHA Accepted TLSv1 128 bits AES128-SHA Accepted TLSv1 128 bits CAMELLIA128-SHA Accepted TLSv1 128 bits RC4-SHA Accepted TLSv1 128 bits RC4-MD5 Accepted TLSv1 112 bits EDH-RSA-DES-CBC3-SHA Accepted TLSv1 112 bits DES-CBC3-SHA how do we turn it off and only allow tlv>=1.1 Kind regards, Matthias Fenner

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[libvirt-users] QemuDomainObjEndJob called when libvirtd is started and libvirt insists qemu is using the wrong disk source.
by Matthew Schumacher 29 Apr '15

29 Apr '15

List, I was under the impression that I could restart libvirtd without it destroying my VMs, but am not finding that to be true. When I killall libvirtd then my VM's keep running, but then when I start libvirtd it calls qemuDomainObjEndJob:1542 : Stopping job: modify (async=none vm=0x7fb8cc0d8510 name=test) and my domain gets whacked. Any way to disable this behavior? Also, while I'm at it, due to issues with snapshotting, I ended up with two domains where libvirt insists the disk source is incorrect which causes many things to break like this: root@wasvirt1:/etc/libvirt# virsh domblklist wasdev Target Source ------------------------------------------------ vda /glustervol1/vm/wasdev/wasdev.reboot hdc /dev/sr0 Yet: root@wasvirt1:/etc/libvirt# lsof | grep wasdev 2235 /usr/bin/qemu-system-x86_64 /var/log/libvirt/qemu/wasdev.log 2235 /usr/bin/qemu-system-x86_64 /var/log/libvirt/qemu/wasdev.log 2235 /usr/bin/qemu-system-x86_64 /glustervol1/vm/wasdev/wasdev.qcow2 The reason is because a blockcommit --active --pivot doesn't work, I blockjob --abort, then try again, it works the second time, but then the disk is wrong. Help would be greatly appreciated. Thanks, schu

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[libvirt-users] Virtual Smartcard GPG
by roky＠openmailbox.org 29 Apr '15

29 Apr '15

Hi. Is is possible to use GPG on the host instead of NSS with virtual smartcards? Please document how or add support for it. Can a virtual smartcard make the host less secure? If there are bugs in GPG/NSS backend on the host can they be abused by untrusted code in the vm?

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[libvirt-users] How does the libvirt deal with the vnet mac address
by wh.h＠foxmail.com 28 Apr '15

28 Apr '15

How does the libvirt deal with the vnet mac address? Greetings, if I establish a network for the VM (hypervisor is KVM) using bridge in the virt-manager , a vnet0 device is created . There are some relationships about mac address between the vnet0 device in the hypervisor and the ethX device in the VM, for example : the mac address of vnet0 is FE:54:00:84:E3:62 the mac address of ethX in the VM is 52:54:00:84:E3:62 two mac addresses above are almost the same except the first part of the address . but if I created a tap device manually , tunctl -t tap0 -u root brctl addif br0 tap0 and add tap0 to the VM, I will find that mac address between the tap0 device in the hypervisor and the ethX device in the VM will totally different . so I think that libvirt must do something about the mac address handling, could you please kindly tell me something about this ? I have found a function in libvirt-0.10.2.8\src\util\ virnetdevtap.c int virNetDevTapCreateInBridgePort(const char *brname, char **ifname, const virMacAddrPtr macaddr, const unsigned char *vmuuid, int *tapfd, virNetDevVPortProfilePtr virtPortProfile, virNetDevVlanPtr virtVlan, unsigned int flags) { …. virMacAddr tapmac; if (virNetDevTapCreate(ifname, tapfd, flags) < 0) return -1; /* We need to set the interface MAC before adding it * to the bridge, because the bridge assumes the lowest * MAC of all enslaved interfaces & we don't want it * seeing the kernel allocate random MAC for the TAP * device before we set our static MAC. */ virMacAddrSet(&tapmac, macaddr); if (!(flags & VIR_NETDEV_TAP_CREATE_USE_MAC_FOR_BRIDGE)) { if (macaddr->addr[0] == 0xFE) { /* For normal use, the tap device's MAC address cannot * match the MAC address used by the guest. This results * in "received packet on vnetX with own address as source * address" error logs from the kernel. */ virReportError(VIR_ERR_CONFIG_UNSUPPORTED, _("Unable to use MAC address starting with " "reserved value 0xFE - '%02X:%02X:%02X:%02X:%02X:%02X' - "), macaddr->addr[0], macaddr->addr[1], macaddr->addr[2], macaddr->addr[3], macaddr->addr[4], macaddr->addr[5]); goto error; } tapmac.addr[0] = 0xFE; /* Discourage bridge from using TAP dev MAC */ //the first part of mac address is set to 0xFE. } if (virNetDevSetMAC(*ifname, &tapmac) < 0) goto error; …. } How does the libvirt establish the arp table in the hypervisor if the vnet0 device in the hypervisor and the ethX device in the VM is different? If I want to create tap device manually , how should I deal with the mac address ?I have setup the mac address of the tap0 device in the hypervisor and the ethX device in the VM in the same way with libvirt , but the network of VM cannot work. weihua wh.h(a)foxmail.com wh.h(a)foxmail.com

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[libvirt-users] Remove Virtual bridge and DNSMASQ
by mimicafe＠gmail.com 24 Apr '15

24 Apr '15

I am running KVM virtualization with libvirtd (libvirt) 0.10.2 in bridged network mode, however I still have the default virtual network bridge/interfaces and dnsmasq on the host. What I am trying to understand is whether or not dnsmasq and the virtual network (*virbr0, Vnet0 and Vnet1*) still play any role. If not, can I remove them? On most virtual hosts I see they are left around even when a network bridge has been manually setup and the default virtual network bridge/interfaces and dnsmasq are not serve any purpose. Thanks Mimi [bigfoot@localhost ~]$ ifconfig br0 Link encap:Ethernet HWaddr E2:59:52:12:34:4C inet addr:135.17.1XX.XX Bcast:135.17.1XX.XX Mask:255.255.255.128 inet6 addr: fe80::ea39:35ff:fe12:948e/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:564577 errors:0 dropped:0 overruns:0 frame:0 TX packets:303315 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:566465184 (540.2 MiB) TX bytes:83532692 (79.6 MiB) eth0 Link encap:Ethernet HWaddr E2:59:52:12:34:4C inet6 addr: fe80::ea39:35ff:fe12:948e/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:806142 errors:0 dropped:0 overruns:0 frame:0 TX packets:450977 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:711888772 (678.9 MiB) TX bytes:175377460 (167.2 MiB) Interrupt:28 Memory:f7100000-f7120000 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:276793 errors:0 dropped:0 overruns:0 frame:0 TX packets:276793 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:551259266 (525.7 MiB) TX bytes:551259266 (525.7 MiB) *virbr0 Link encap:Ethernet HWaddr 52:54:00:2A:1B:AF* * inet addr:192.168.122.1 Bcast:192.168.122.255 Mask:255.255.255.0* * UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1* * RX packets:0 errors:0 dropped:0 overruns:0 frame:0* * TX packets:0 errors:0 dropped:0 overruns:0 carrier:0* * collisions:0 txqueuelen:0* * RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)* *vnet0 Link encap:Ethernet HWaddr FE:54:00:A0:8D:50* * inet6 addr: fe80::fc54:ff:fea0:8d50/64 Scope:Link* * UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1* * RX packets:124812 errors:0 dropped:0 overruns:0 frame:0* * TX packets:343055 errors:0 dropped:0 overruns:0 carrier:0* * collisions:0 txqueuelen:500* * RX bytes:55075362 (52.5 MiB) TX bytes:138488556 (132.0 MiB)* *vnet1 Link encap:Ethernet HWaddr FE:54:00:71:A8:78* * inet6 addr: fe80::fc54:ff:fe71:a878/64 Scope:Link* * UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1* * RX packets:17834 errors:0 dropped:0 overruns:0 frame:0* * TX packets:318816 errors:0 dropped:0 overruns:1 carrier:0* * collisions:0 txqueuelen:500* * RX bytes:2279102 (2.1 MiB) TX bytes:20534286 (19.5 MiB)* [bigfoot@localhost ~]$

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[libvirt-users] CfP Virtualization in High-Performance Cloud Computing Workshop (VHPC '15)
by VHPC 15 24 Apr '15

24 Apr '15

================================================================= CALL FOR PAPERS 10th Workshop on Virtualization in High-Performance Cloud Computing (VHPC '15) held in conjunction with Euro-Par 2015, August 24-28, Vienna, Austria (Springer LNCS) ================================================================= Date: August 25, 2015 Workshop URL: http://vhpc.org Paper Submission Deadline: May 22, 2015 CALL FOR PAPERS Virtualization technologies constitute a key enabling factor for flexible resource management in modern data centers, cloud environments, and increasingly in HPC as well. Providers need to dynamically manage complex infrastructures in a seamless fashion for varying workloads and hosted applications, independently of the customers deploying software or users submitting highly dynamic and heterogeneous workloads. Thanks to virtualization, we have the ability to manage vast computing and networking resources dynamically and close to the marginal cost of providing the services, which is unprecedented in the history of scientific and commercial computing. Docker et al. OS-level virtualization, with its capability to isolate multiple user-space environments allows for their co-existence within the same OS kernel. It promises to provide many of the advantages of machine virtualization with high levels of responsiveness and performance; coupled with lightweight OSs it forms a potent architecture with promise to become a mainstream environment for HPC workloads. Machine virtualization, with its capability to enable consolidation of multiple under-utilized servers with heterogeneous software and operating systems (OSes), and its capability to live-migrate a fully operating virtual machine (VM) with a very short downtime, enables novel and dynamic ways to manage physical servers; I/O Virtualization allows physical network adapters to take traffic from multiple VMs; network virtualization, with its capability to create logical network overlays that are independent of the underlying physical topology and IP addressing, provides the fundamental ground on top of which evolved network services can be realized with an unprecedented level of dynamicity and flexibility; These technologies have to be inter-mixed and integrated in an intelligent way, to support workloads that are increasingly demanding in terms of absolute performance, responsiveness and interactivity, and have to respect well-specified Service- Level Agreements (SLAs), as needed for industrial-grade provided services. The Workshop on Virtualization in High-Performance Cloud Computing (VHPC) aims to bring together researchers and industrial practitioners facing the challenges posed by virtualization in order to foster discussion, collaboration, mutual exchange of knowledge and experience, enabling research to ultimately provide novel solutions for virtualized computing systems of tomorrow. The workshop will be one day in length, composed of 20 min paper presentations, each followed by 10 min discussion sections, and lightning talks, limited to 5 minutes. Presentations may be accompanied by interactive demonstrations. TOPICS Topics of interest include, but are not limited to: - Virtualization in supercomputing environments, HPC clusters, cloud HPC and grids - OS-level virtualization including container runtimes (Docker, rkt et al.) - Lightweight compute node operating systems/VMMs - Optimizations of virtual machine monitor platforms, hypervisors and - Hypervisor and network virtualization QoS and SLAs - Cloud based network and system management for SDN and NFV - Management, deployment and monitoring of virtualized environments - Performance measurement, modelling and monitoring of virtualized/cloud workloads - Programming models for virtualized environments - Cloud reliability, fault-tolerance, high-availability and security - Heterogeneous virtualized environments, virtualized accelerators, GPUs and co-processors - Optimized communication libraries/protocols in the cloud and for HPC in the cloud - Topology management and optimization for distributed virtualized applications - Cluster provisioning in the cloud and cloud bursting - Adaptation of emerging HPC technologies (high performance networks, RDMA, etc..) - I/O and storage virtualization, virtualization aware file systems - Job scheduling/control/policy in virtualized environments - Checkpointing and migration of VM-based large compute jobs - Cloud frameworks and APIs - Energy-efficient / power-aware virtualization Important Dates April 29, 2015 - Abstract registration May 22, 2015 - Full paper submission June 19, 2015 - Acceptance notification October 2, 2015 - Camera-ready version due August 25, 2015 - Workshop Date TPC CHAIR Michael Alexander (chair), TU Wien, Austria Anastassios Nanos (co-chair), NTUA, Greece Balazs Gerofi (co-chair), RIKEN Advanced Institute for Computational Science, Japan PROGRAM COMMITTEE Stergios Anastasiadis, University of Ioannina, Greece Costas Bekas, IBM Zurich Research Laboratory, Switzerland Jakob Blomer, CERN Ron Brightwell, Sandia National Laboratories, USA Roberto Canonico, University of Napoli Federico II, Italy Julian Chesterfield, OnApp, UK Patrick Dreher, MIT, USA William Gardner, University of Guelph, Canada Kyle Hale, Northwestern University, USA Marcus Hardt, Karlsruhe Institute of Technology, Germany Iftekhar Hussain, Infinera, USA Krishna Kant, Temple University, USA Eiji Kawai, National Institute of Information and Communications Technology, Japan Romeo Kinzler, IBM, Switzerland Kornilios Kourtis, ETH, Switzerland Nectarios Koziris, National Technical University of Athens, Greece Massimo Lamanna, CERN Che-Rung Roger Lee, National Tsing Hua University, Taiwan William Magato, University of Cincinnati, USA Helge Meinhard, CERN Jean-Marc Menaud, Ecole des Mines de Nantes France Christine Morin, INRIA, France Amer Qouneh, University of Florida, USA Seetharami Seelam, IBM Watson Research Center, USA Josh Simons, VMWare, USA Borja Sotomayor, University of Chicago, USA Kurt Tutschku, Blekinge Institute of Technology, Sweden Yasuhiro Watashiba, Osaka University, Japan Chao-Tung Yang, Tunghai University, Taiwan PAPER SUBMISSION-PUBLICATION Papers submitted to the workshop will be reviewed by at least two members of the program committee and external reviewers. Submissions should include abstract, key words, the e-mail address of the corresponding author, and must not exceed 10 pages, including tables and figures at a main font size no smaller than 11 point. Submission of a paper should be regarded as a commitment that, should the paper be accepted, at least one of the authors will register and attend the conference to present the work. Accepted papers will be published in the Springer LNCS series - the format must be according to the Springer LNCS Style. Initial submissions are in PDF; authors of accepted papers will be requested to provide source files. Format Guidelines: http://www.springer.de/comp/lncs/authors.html Submission Link: https://easychair.org/conferences/?conf=europar2015ws GENERAL INFORMATION The workshop is one day in length and will be held in conjunction with Euro-Par 2015, 24-28 August, Vienna, Austria

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