January 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] Libvirt bite sized tasks
by Michal Privoznik 20 Mar '16

20 Mar '16

Dear lists, I've just started new wiki page which aim is to summarize small and trivial tasks, that starting contributors can take, investigate and implement. The aim is to give them something easy to start with while not scaring them out about complexity of our code. The page can be found here: http://wiki.libvirt.org/page/BiteSizedTasks The name is copied from qemu wiki: http://wiki.qemu.org/BiteSizedTasks Please, feel free to extend the list. I plan to use it in the future when interviewing GSoC candidates. Michal

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[libvirt-users] Zombie processes being created when console buffer is full
by Peter Steele 10 Mar '16

10 Mar '16

We have been researching stuck zombie processes in our libvirt lxc containers. What we found was: 1) Each zombie’s parent was pid 1. init which symlinks to systemd. 2) In some cases, the zombies were launched by systemd, in others the zombie was inherited. 3) While the child is in the zombie state, the parent process (systemd) /proc/1/status shows no pending signals. 4) Attaching gdb to systemd, there was 1 thread and it was waiting in write() and the file being written was /dev/console. This write() to the console never returns. We operated under the assumption that systemd's SIGCHLD handler sets a bit and a foreground thread (the only thread) would see that child processes needed reaping. While the single thread is stuck in write(), the reaping never takes place. So why is write() blocking? The answer seems to be that there is nothing draining the console and eventually it blocks write() when its buffers become full. When we attached to the container's console, the buffer is cleared allowing systemd’s write() to return. The zombies are then reaped and everything goes back to normal. Our “solution” was more of a workaround. systemd was altered to log errors/warnings/etc to /dev/null instead of /dev/console. This prevented the problem, only in that the console buffer was unlikely to get filled up since systemd generally is the only then that writes to it. This is definitely a hack though. This may be a bug in the libvirt container library (you can't expect something to periodically connect to a container's console to empty it out). We suspect there may also be a configuration issue in our containers with regards to the console. Has anyone else observed this problem? Peter _______________________________________________ libvirt-users mailing list libvirt-users(a)redhat.com https://www.redhat.com/mailman/listinfo/libvirt-users

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[libvirt-users] UserID Permissions: Virtual Machine Manager vs virsh and Python
by David Ashley 22 Feb '16

22 Feb '16

I have added a user to the libvirt group on my CentOS 7.2 server and that user can successfully access the Virtual Machine Manager without authenticating as expected. This allows the user to perform all functions in the VMS as if they were root. This is acceptable as this is a private server with no outside access so security is not a real issue. But when that same user tries to perform functions with virsh or using a Python script that uses the libvirt module, the connection is just read-only. Why are the permissions different for these environments and what must I do to give the user r/w access in virsh or the Python script? David Ashley

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[libvirt-users] Networking with qemu/kvm+libvirt
by Andre Goree 09 Feb '16

09 Feb '16

I have some questions regarding the way that networking is handled via qemu/kvm+libvirt -- my apologies in advance if this is not the proper mailing list for such a question. I am trying to determine how exactly I can manipulate traffic from a _guest's_ NIC using iptables on the _host_. On the host, there is a bridged virtual NIC that corresponds to the guest's NIC. That interface does not have an IP setup on it on the host, however within the vm itself the IP is configured and everything works as expected. During my testing, I've seemingly determined that traffic from the vm does NOT traverse iptables on the host, but I _can_ in fact see the traffic via tcpdump on the host. This seems odd to me, unless the traffic is passed on during interaction with the kernel, and thus never actually reaches iptables. I've gone as far as trying to log via iptables any and all traffic traversing the guest's interface on the host, but to no avail (iptables does not see any traffic from the guest's NIC on the host). Is this the way it's supposed to work? And if so, is there any way I can do IP/port redirection silently on the _host_? Thanks in advance for any insight that anyone can share :) -- Andre Goree -=-=-=-=-=- Email - andre at drenet.net Website - http://www.drenet.net PGP key - http://www.drenet.net/pubkey.txt -=-=-=-=-=-

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[libvirt-users] generate interface MAC addresses in a particular order
by Andrei Perietanu 01 Feb '16

01 Feb '16

Hi all, I am using libvirt to manage VM on my system; after creating a VM (default no NICs are present in the configuration) you can add any number of interfaces to it (as long as they exist on the host). To do that, I edit the configuration xlm: vmXml = self.domain.XMLDesc() root = ET.fromstring(vmXml) devices = root.find('./devices') intf = ET.SubElement(devices,'interface') intf.set('type', 'bridge') src = ET.SubElement(intf,'source') src.set('bridge', bIntf) model = ET.SubElement(intf,'model') model.set('type', 'e1000') xml = ET.tostring(root) self.conn.defineXML(xml) Now the problem I have is that the MAC addresses are auto-generated and because of this there is no way to predict which interface number the newly added interface will map to, on the VM. Ideally, the first added interface is mapped to eth0/0, the second one eth0/1...etc. Since the mappings depend on the MAC addresses I figured that is the part I need to have control over. Any ideas? Thanks, Andrei -- The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of or taking of any action in reliance upon this information by persons or entities other than the intended recipient is prohibited. If you receive this in error please contact the sender and delete the material from any computer immediately. It is the policy of Klas Limited to disavow the sending of offensive material and should you consider that the material contained in the message is offensive you should contact the sender immediately and also your I.T. Manager. Klas Telecom Inc., a Virginia Corporation with offices at 1101 30th St. NW, Washington, DC 20007. Klas Limited (Company Number 163303) trading as Klas Telecom, an Irish Limited Liability Company, with its registered office at Fourth Floor, One Kilmainham Square, Inchicore Road, Kilmainham, Dublin 8, Ireland.

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[libvirt-users] storage pool and volume usage question
by Paul Carlton 31 Jan '16

31 Jan '16

Hi I'm creating a storage volume in a storage pool (directory type). I'd like to create a volume that creates a file in a sub directory under the directory that the pool points to but am not able to work out how, maybe it is not possible? My pool was created using following xml... <pool type='dir'> <name>nova-local-pool</name> <target> <path>/home/pcarlton/openstack/stuff/instances</path> <permissions> <mode>0755</mode> <owner>1000</owner> <group>130</group> </permissions> </target> </pool> The volume was created using this xml... stgvol_xml = """ <volume> <name>4291f96a-759a-4b8a-bfe2-7a8ccb118b75-disk</name> <allocation>0</allocation> <capacity unit="G">1</capacity> <target> <format type='qcow2'/> <permissions> <owner>1000</owner> <group>130</group> <mode>0644</mode> <label>image_overlay</label> </permissions> </target> <backingStore> <path>/home/pcarlton/openstack/stuff/nova/instances/_base/07f224f72581f8e029e08ff96827d581b2321a7b</path> <format type='raw'/> <permissions> <owner>1000</owner> <group>130</group> <mode>0644</mode> <label>image_base</label> </permissions> </backingStore> </volume>""" All works ok but I'd like the create the 'disk' file in /home/pcarlton/openstack/stuff/nova/instances/4291f96a-759a-4b8a-bfe2-7a8ccb118b75 Thanks -- Paul Carlton Software Engineer Cloud Services Hewlett Packard Enterprise BUK03:T242 Longdown Avenue Stoke Gifford Bristol BS34 8QZ Mobile: +44 (0)7768 994283 Office: +44 (0)117 316 2189 Email: mailto:paul.carlton2@hpe.com irc: paul-carlton2 Hewlett-Packard Enterprise Limited registered Office: Cain Road, Bracknell, Berks RG12 1HN Registered No: 690597 England. The contents of this message and any attachments to it are confidential and may be legally privileged. If you have received this message in error, you should delete it from your system immediately and advise the sender. To any recipient of this message within HP, unless otherwise stated you should consider this message and attachments as "HP CONFIDENTIAL".

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[libvirt-users] virt-viewer and virt-manager problem
by Pascal Legrand 29 Jan '16

29 Jan '16

Hello, here is my problem : i migrated an old debian server, with kvm host and guests vm, on a new one (wheezy to jessie). Everything worked fine on this old server. On the new server, i created a storage pool, copy the qcow2 guests files (from the old server) inside this storage pool, copy the xml guests files (from the old server) to /etc/libvirt/qemu , then virsh define guests and virsh start guests. Every guests works fine. My problem is about virt-viewer and virt-manager when i connect from my station to my kvm host from ssh (ssh -X 192.168.151.248). I cant use virt-manager or virt-user virt-manager display all the guests but i cant display the guest itself or the guest informations virt-viewer open a blanck window when i do vncviewer 192.168.151.248:5906 it works fine then i think the problem come from virt-viewer and virt-manager, but i cant see where is the problem. Does someone could help to solve this problem. Thanks -- Pascal

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[libvirt-users] Zombie processes being created when console buffer is full
by Peter Steele 29 Jan '16

29 Jan '16

We have been researching stuck zombie processes in our libvirt lxc containers. What we found was: 1) Each zombie’s parent was pid 1. init which symlinks to systemd. 2) In some cases, the zombies were launched by systemd, in others the zombie was inherited. 3) While the child is in the zombie state, the parent process (systemd) /proc/1/status shows no pending signals. 4) Attaching gdb to systemd, there was 1 thread and it was waiting in write() and the file being written was /dev/console. This write() to the console never returns. We operated under the assumption that systemd's SIGCHLD handler sets a bit and a foreground thread (the only thread) would see that child processes needed reaping. While the single thread is stuck in write(), the reaping never takes place. So why is write() blocking? The answer seems to be that there is nothing draining the console and eventually it blocks write() when its buffers become full. When we attached to the container's console, the buffer is cleared allowing systemd’s write() to return. The zombies are then reaped and everything goes back to normal. Our “solution” was more of a workaround. systemd was altered to log errors/warnings/etc to /dev/null instead of /dev/console. This prevented the problem, only in that the console buffer was unlikely to get filled up since systemd generally is the only then that writes to it. This is definitely a hack though. This may be a bug in the libvirt container library (you can't expect something to periodically connect to a container's console to empty it out). We suspect there may also be a configuration issue in our containers with regards to the console. Has anyone else observed this problem? Peter

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