July 2016 - Users - libvirt List Archives

[libvirt-users] ceph rbd pool and libvirt manageability (virt-install)
by Jelle de Jong 28 Aug '18

28 Aug '18

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hello everybody, I created a rbd pool and activated it, but I can't seem to create volumes in it with virsh or virt-install? # virsh pool-dumpxml myrbdpool <pool type='rbd'> <name>myrbdpool</name> <uuid>2d786f7a-2df3-4d79-ae60-1535bcf1c6b5</uuid> <capacity unit='bytes'>6997998301184</capacity> <allocation unit='bytes'>10309227031</allocation> <available unit='bytes'>6977204658176</available> <source> <host name='ceph01.powercraft.nl' port='6789'/> <host name='ceph02.powercraft.nl' port='6789'/> <host name='ceph03.powercraft.nl' port='6789'/> <name>libvirt-pool</name> <auth type='ceph' username='libvirt'> <secret uuid='029a334e-ed57-4293-bb99-ffafa8867122'/> </auth> </source> </pool> # virt-install --version 1.0.1 # virsh --version 1.2.9 I ended using virsh edit ceph-test.powercraft.nl and making creating the disk manually. <disk type='network' device='disk'> <auth username='libvirt'> <secret type='ceph' uuid='029a334e-ed57-4293-bb99-ffafa8867122'/> </auth> <source protocol='rbd' name='libvirt-pool/kvm01-storage'> <host name='ceph01.powercraft.nl' port='6789'/> <host name='ceph02.powercraft.nl' port='6789'/> <host name='ceph03.powercraft.nl' port='6789'/> </source> <target dev='vdc' bus='virtio'/> </disk> I use virt-install a lot to define, import and undefine domains, how can I use virt-install to manage my rdb disks? Kind regards, Jelle de Jong -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iJwEAQECAAYFAlV1xlQACgkQ1WclBW9j5HkbPQP+PjNrzvlqysslOp2Yk7wH4Mxy 2sh2dn96G0KOAHEeEn3BN6IWlnD1TADZbHdpTtMwkdv48Xwn0sP1s+3QDM4pb3gP n+z+dVxS8FouDIy/eiso3IBCj3g4TWbEX8ZHqs3jKqe0lZgAXBzB9xYSUowcEBrZ ddkPbr8p8ozWyOG+9V8= =lkK7 -----END PGP SIGNATURE-----

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[libvirt-users] virRandomBits - not very random
by Brian Rak 01 Jun '18

01 Jun '18

I just ran into an issue where I had about 30 guests get duplicate mac addresses assigned. These were scattered across 30 different machines. Some debugging revealed that: 1) All the host machines were restarted within a couple seconds of each other 2) All the host machines had fairly similar libvirtd pids (within ~100 PIDs of each other) 3) Libvirt seeds the RNG using 'time(NULL) ^ getpid()' This perfectly explains why I saw so many duplicate mac addresses. Why is the RNG seed such a predictable value? Surely there has to be a better source of a random seed then the timestamp and the pid? The PID seems to me to be a very bad source of any randomness. I just ran a test across 60 of our hosts. 43 of them shared their PID with at least one other machine.

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[libvirt-users] stream finish throws exception via python API
by Shahar Havivi 27 Nov '16

27 Nov '16

Hi, The following snippet works fine e.g. receiving the data but when calling stream.finish() we get the following error: stream = con.newStream() vol.download(stream, 0, 0, 0) buf = stream.recv(1024) stream.finish() libvirt: I/O Stream Utils error : internal error: I/O helper exited abnormally Traceback (most recent call last): File "./helpers/kvm2ovirt", line 149, in <module> download_volume(vol, item[1], diskno, disksitems, pksize) File "./helpers/kvm2ovirt", line 102, in download_volume stream.finish() File "/usr/lib64/python2.7/site-packages/libvirt.py", line 5501, in finish if ret == -1: raise libvirtError ('virStreamFinish() failed') libvirt.libvirtError: internal error: I/O helper exited abnormally Am I doing something wrong? Thank you, Shahar.

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[libvirt-users] Lifecycle of a connection to libvirtd
by Vincent Bernat 26 Aug '16

26 Aug '16

Hey! I am trying to figure out how to reliably maintain a connection to libvirtd. From the documentation, I would expect something like that: - virConnectOpen() - virConnectRegisterCloseCallback() - virConnectSetKeepAlive() - Application logic And in the registered callback, I would: - virConnectUnregisterCloseCallback() - virConnectClose() - virConnectOpen() - virConnectRegisterCloseCallback() - virConnectSetKeepAlive() However, looking at the source code of virsh, I see that it additional stuff, notably: - virConnectIsAlive() - checking error codes of all calls to check if they are the result of a disconnect Are those steps needed? Randomly checking virConnectIsAlive() doesn't seem reliable. Checking individual error codes either (maybe I will miss one of them or misinterpret another one). virsh code uses those error codes to check if there is a disconnection: (((last_error->code == VIR_ERR_SYSTEM_ERROR) && (last_error->domain == VIR_FROM_REMOTE)) || (last_error->code == VIR_ERR_RPC) || (last_error->code == VIR_ERR_NO_CONNECT) || (last_error->code == VIR_ERR_INVALID_CONN)))) Any hint? -- Program defensively. - The Elements of Programming Style (Kernighan & Plauger)

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[libvirt-users] QEMU IMG vs Libvirt block commit
by Erlon Cruz 12 Aug '16

12 Aug '16

Hi folks, I'm having a issue in the standard NFS driver on OpenStack, that uses qemu-img and libvirt to create snapshots of volumes. It uses qemu-img in the Controller to manage the snapshots when the volume is not attached (offline) or calls the Compute (which calls libvirt) to manage snapshots if the volume is attached (online). When I try to create/delete snapshots from a snapshot chain. There are 3 situations: 1 - I create/delete the snapshots in Cinder (it uses qemu-img). It goes OK! I can delete and I can create snapshots. 2 - I create/delete the snapshots, in online mode (it uses libvirt). It goes Ok, as weel. 3 - I create the snapshots in Cinder (offline) and delete then in online mode (using libvirt), then it fails with this message[1]: libvirtError: invalid argument: could not find image 'volume-13cb83a2-880f-40e8-b60e-7e805eed76f9.d024731c-bdc3-4943-91c0-215a93ee2cf4' in chain for '/opt/stack/data/nova/mnt/a3b4c6ddd9bf82edd4f726872be58d05/volume-13cb83a2-880f-40e8-b60e-7e805eed76f9' But, in this folder, there the backing files are there[2] and they are chained as think it suppose to be[3]. The version for the 2 hosts in tests are: Controller/Cinder node: qemu-img version 2.0.0 && libvirt 1.2.2-0ubuntu13 Compute node: qemu-img version 2.5.0 && libvirt-1.3.1-1ubuntu10 Is there any compatibility problem between libvirt and qemu-img snapshots? Have you guys found any problem like that? Erlon ---------------------------------- [1] http://paste.openstack.org/show/543270/ [2] http://paste.openstack.org/show/543273/ [3] http://paste.openstack.org/show/543274/

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[libvirt-users] NPIV storage pools do not map to same LUN units across hosts.
by Nitesh Konkar 04 Aug '16

04 Aug '16

Link: http://wiki.libvirt.org/page/NPIV_in_libvirt Topic: Virtual machine configuration change to use vHBA LUN There is a NPIV storage pool defined on two hosts and pool contains a total of 8 volumes, allocated from a storage device. Source: # virsh vol-list poolvhba0 Name Path ------------------------------------------------------------------------------ unit:0:0:0 /dev/disk/by-id/wwn-0x6005076802818bda3000000000000366 unit:0:0:1 /dev/disk/by-id/wwn-0x6005076802818bda3000000000000367 unit:0:0:2 /dev/disk/by-id/wwn-0x6005076802818bda3000000000000368 unit:0:0:3 /dev/disk/by-id/wwn-0x6005076802818bda3000000000000369 unit:0:0:4 /dev/disk/by-id/wwn-0x6005076802818bda300000000000036a unit:0:0:5 /dev/disk/by-id/wwn-0x6005076802818bda3000000000000380 unit:0:0:6 /dev/disk/by-id/wwn-0x6005076802818bda3000000000000381 unit:0:0:7 /dev/disk/by-id/wwn-0x6005076802818bda3000000000000382 -------------------------------------------------------------------- Destination: -------------------------------------------------------------------- # virsh vol-list poolvhba0 Name Path ------------------------------------------------------------------------------ unit:0:0:0 /dev/disk/by-id/wwn-0x6005076802818bda3000000000000380 unit:0:0:1 /dev/disk/by-id/wwn-0x6005076802818bda3000000000000381 unit:0:0:2 /dev/disk/by-id/wwn-0x6005076802818bda3000000000000382 unit:0:0:3 /dev/disk/by-id/wwn-0x6005076802818bda3000000000000367 unit:0:0:4 /dev/disk/by-id/wwn-0x6005076802818bda3000000000000368 unit:0:0:5 /dev/disk/by-id/wwn-0x6005076802818bda3000000000000366 unit:0:0:6 /dev/disk/by-id/wwn-0x6005076802818bda300000000000036a unit:0:0:7 /dev/disk/by-id/wwn-0x6005076802818bda3000000000000369 -------------------------------------------------------------------- As you can see in the above output,the same set of eight LUNs from the storage server have been mapped, but the order that the LUNs are probed on each host is different, resulting in different unit names on the two different hosts . If the the guest XMLs is referencing its storage by "unit" number then is it safe to migrate such guests because the "unit number" is assigned by the driver according to the specific way it probes the storage and hence when you migrate these guests , it results in different unit names on the destination hosts. Thus the migrated guest gets mapped to the wrong LUNs and is given the wrong disks. The problem is that the LUN numbers on the destination host and source host do not agree. Example, LUN 0 on source_host, for example, may be LUN 5 on destination_host. When the guest is given the wrong disk, it suffers a fatal I/O error. (This is manifested as fatal I/O errors since the guest has no idea that its disks just changed out under it.)The migration does not take into account that the unit numbers do match on on the source and destination sides. So, should libvirt make sure that the guest domains reference NPIV pool volumes by their globally-unique wwn instead of by "unit" numbers? The guest XML references its storage by "unit" number. Eg:- <disk type='volume' device='lun'> <driver name='qemu' type='raw' cache='none'/> <source pool='poolvhba0' volume='unit:0:0:0'/> <backingStore/> <target dev='vdb' bus='virtio'/> <alias name='virtio-disk1'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/> </disk> I am planning to write a patch for it. Any comments on the above observation/approach would be appreciated. Thanks, Nitesh.

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[libvirt-users] Live Disk Backup
by Prof. Dr. Michael Schefczyk 01 Aug '16

01 Aug '16

Dear All, using CentOS 7.2.1511, and libvirt from ovirt repositories (currently 1.2.17-13.el7_2.5, but without otherwise using ovirt) I am regularly backing up my VMs which are on qcow2 files. In general, I am trying to follow http://wiki.libvirt.org/page/Live-disk-backup-with-active-blockcommit A typical backup script would be #!/bin/bash dt=`date +%y%m%d` if virsh dominfo dockers10a | grep -q -E '^Status: *laufend|^State: *running' then virsh snapshot-create-as --domain dockers10a dockers10a --diskspec vda,file=/home/dockers10asnap.qcow2 --disk-only --no-metadata --atomic cp /kvm01/dockers10a.qcow2 /backup/dockers10a$dt.qcow2 virsh blockcommit dockers10a vda --active --verbose --pivot virsh snapshot-delete dockers10a dockers10a rm /home/dockers10asnap.qcow2 fi I am fully aware that the third line from the end "virsh snapshot-delete ..." will fail under regular circumstances. It is just there as a precaution to delete unnecessary snapshots should a previous backup have failed. For some time, I am noticing that from time to time backup fails in the way that the xml definition file of the VM backed up keeps the temporary file (in the example above /home/dockers10asnap.qcow2) as the source file. Then, at least upon rebooting the host, it will be unable to restart the VM. In addition, lots of other troubles can arise (following backups failing, storage issues). I am using a similar setup on four hosts. It seems that the better the resources of the host are, the lower the likelihood of the problem occurring - but that cannot be an acceptable state. Can someone please point me to how to avoid this? Regards, Michael Schefczyk

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[libvirt-users] Network without forward mode
by Vincent Bernat 28 Jul '16

28 Jul '16

Hey! Another question. The documentation about networks say: ╭─────┤ http://libvirt.org/formatnetwork.html#elementsConnect ├───── │Inclusion of the forward element indicates that the virtual network is │to be connected to the physical LAN.Since 0.3.0. The mode attribute │determines the method of forwarding. If there is no forward element, the │network will be isolated from any other network (unless a guest │connected to that network is acting as a router, of course). ╰───── That's exactly what I want: just a vnet interface, no bridge, no routing, no forwarding. However, if I create a network with just that: #v+ <network> <name>public</name> <uuid>4629ba54-9e33-4a1f-9e45-78a1c8faaddc</uuid> </network> #v- libvirt (2.0.0) adds a bridge stanza: #v+ <network> <name>public</name> <uuid>4629ba54-9e33-4a1f-9e45-78a1c8faaddc</uuid> <bridge name='virbr1' stp='on' delay='0'/> <mac address='52:54:00:15:45:da'/> </network> #v- The bridge is created. If I spawn a VM attached to this network, it gets added to the bridge. Any way to have a network where absolutely no setup is done? Thanks! -- Use the "telephone test" for readability. - The Elements of Programming Style (Kernighan & Plauger)

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[libvirt-users] Routing isolated network
by Erwin Straver 28 Jul '16

28 Jul '16

I want to create a network like this: Internet -- physical router -- host (network 192.168.178.x) -- virtual machine dmz -- eth0 (connected to pyshical router) -- eth1 (connect to isolated network 10.0.0.x) -- virtual machine www - eth0 (connect to isolated network 10.0.0.x) [image: network design] <http://i.stack.imgur.com/QoCz9.png> I have a virtual host which is conntected to my physical router with eth0 and ip4 address 192.168.178.100. I create a virtual machine dmz which connects 'direct' to my router via my physical device eth0 on the virtual host: <network connections='1'> <name>direct</name> <uuid>379d4687-445e-4bc6-8354-b555c7f18b15</uuid> <forward dev='eth0' mode='bridge'> <interface dev='eth0' connections='1'/> </forward> </network> On my virtual machine i create a second nic eth1 which is connected on a virtual network virbr-local: <network> <name>local</name> <uuid>d31b2e0d-810b-4ba0-8ac4-02bc53746142</uuid> <bridge name='virbr-local' stp='on' delay='0'/> <mac address='52:54:00:92:06:5c'/> <domain name='local.box'/> <dns> <forwarder addr='192.168.178.1'/> </dns> <ip address='10.0.0.1' netmask='255.0.0.0'> <dhcp> <range start='10.0.0.100' end='10.0.0.255'/> <host mac='52:54:00:51:31:86' ip='10.0.0.30'/> </dhcp> </ip> <route address='10.0.0.0' prefix='8' gateway='10.0.0.30'/> </network> Now I want to create a second virtual machine which connects to the internet through the virtual machine dmz on the virbr-local subnet. Is there a way to accomplish this kind of setup? My routing table on the virtual host looks likes this: Destination Gateway Genmask Flags Metric Ref Use Iface default fritz.box 0.0.0.0 UG 0 0 0 eth0 10.0.0.0 * 255.0.0.0 U 0 0 0 virbr-local 10.0.0.0 10.0.0.30 255.0.0.0 UG 1 0 0 virbr-local 192.168.178.0 * 255.255.255.0 U 0 0 0 eth0 But when I want to ping an address from the www virtual machine I get a unreachable network message. I setup a DNAT om the virtual machine dmz. But looking witch tcpdump on eht1 there's no traffic.I appreciate some help to setup the network. I clearly missing something. Get a signature like this: Click here! <http://ws-promos.appspot.com/r?rdata=eyJydXJsIjogImh0dHA6Ly93d3cud2lzZXN0YW…>

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Re: [libvirt-users] How can I run command in containers on the host?
by Daniel P. Berrange 26 Jul '16

26 Jul '16

On Tue, Jul 26, 2016 at 05:19:22PM +0800, John Y. wrote: > Hi Daniel, > > I forgot to tell you that I using mips64 fedora. Has any effect on this > case? > 2016-07-26 09:05:59.634+0000: 16406: debug : virDomainLxcEnterNamespace:131 > : dom=0xaaad4067c0, (VM: name=fedora2, > uuid=42b97e4d-54dc-41b4-b009-2321a1477a9a), nfdlist=0, fdlist=0xaaad4007c0, > noldfdlist=(nil), oldfdlist=(nil), flags=0 > libvirt: error : Expected at least one file descriptor > error: internal error: Child process (16406) unexpected exit status 125 This is shows nfdlist=0, whicih means that virDomainLxcOpenNamespace didn't provide any file descriptors. This in turn seems to suggest that /proc/$PID/ns didn't contain any files. Is this perhaps a misconfiguration of the mips kernel. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|

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