October 2021 - Users - libvirt List Archives

[libvirt-users] bridge / ubuntu / no arp reply
by François Chenais 15 Oct '26

15 Oct '26

Hello I'm trying to setup a bridged guest on an ubuntu 13.10 but it doesn't work. (Everything is ok with NAT) Network sniffing shows that arp replies don't come back to the guest. Test 1 ------ Guest : ping host_bridge_ip (ok) Test 2 ------ Guest: ping other_lan_host (KO) other_lan_host - receives arp who-is request - sends arp reply - arp -a shows the guest macaddr => Guest doesn't receive reply Test 3 ------ other_lan_host ping the Guest (KO) - arp -a shows "incomplete" addr - Guest receives nothing On Host ------- network tcpdump on bridge or vnet interfaces shows request but no reply ... Thanks in advance for help or ideas François

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[libvirt-users] [virtual interface] detach interface during boot succeed with no changes
by Yalan Zhang 08 Sep '22

08 Sep '22

Hi guys, when I detach an interface from vm during boot (vm boot not finished), it always fail. I'm not sure if there is an existing bug. I have confirmed with someone that for disk, there is similar behavior, if this is also acceptable? # virsh destroy rhel7.2; virsh start rhel7.2 ;sleep 2; virsh detach-interface rhel7.2 network 52:54:00:98:c4:a0; sleep 2; virsh dumpxml rhel7.2 |grep /interface -B9 Domain rhel7.2 destroyed Domain rhel7.2 started Interface detached successfully <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/> </controller> <interface type='network'> <mac address='52:54:00:98:c4:a0'/> <source network='default' bridge='virbr0'/> <target dev='vnet0'/> <model type='rtl8139'/> <alias name='net0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> </interface> When I detach after the vm boot, expand the sleep time to 10, it will succeed. # virsh destroy rhel7.2; virsh start rhel7.2 ;sleep 10; virsh detach-interface rhel7.2 network 52:54:00:98:c4:a0; sleep 2; virsh dumpxml rhel7.2 |grep /interface -B9 Domain rhel7.2 destroyed Domain rhel7.2 started Interface detached successfully ------- Best Regards, Yalan Zhang IRC: yalzhang Internal phone: 8389413

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a test email (& dmarc) @admins
by lejeczek 10 Dec '21

10 Dec '21

hi guys. I sent email a while ago and I wonder, also having not received a single reply, because I did not get that own email - is there are problem I'm having here or DMARC(yahoo & others?) are not fixed in by this mailing list - would an admin(anybody) know? many thanks, L.

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another upgrade another vm issue
by daggs 31 Oct '21

31 Oct '21

Greetings, so I've upgraded my server and yet again, one of my vm lost a functionally. there is no usable sound card. xml: https://dpaste.com/CVR5M75VH in vm: https://snipboard.io/aZ7Dcf.jpg outputs: utils_server /home/igor # qemu-system-x86_64 --version QEMU emulator version 6.0.0 Copyright (c) 2003-2021 Fabrice Bellard and the QEMU Project developers utils_server /home/igor # libvirtd --version libvirtd (libvirt) 7.8.0 utils_server /home/igor # any ideas? Thanks.

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Iptables, et al best practices for protecting KVM host sharing "hostdev" (ixgbe-vf) interfaces with guests
by Philip Prindeville 29 Oct '21

29 Oct '21

Hi, I'm a developer and I use VM's for testing patches before submitting them (for various linux-* projects, as well as downstream things like OpenWrt, EPEL, etc). I have a trunked 10Gb/s Ethernet connection coming into my KVM servers (all of which are Supermicro x86_servers running CentOS 8) that have igb and ixgbe NIC's, so SR-IOV capable. Here's the situation: * the host is on a secured internal network, called "sandbox", which is VLAN 4. * the "external" network (i.e. public facing on my ISP) is "dirty", and is VLAN 66. * the main subnet that laptops, WAPs, desktops, etc. sit on is "main", and is VLAN 1. The KVM hosts sit wholly inside "sandbox". They host, however, several guests some of which sit on "main", and some of which sit on "main" and "external" (for instance, if I'm testing an OpenWrt firewall configuration with patches and it needs to be publicly accessible so that my testers can peer with it via IPsec). Oh, and one production guest which hosts "git" and sits only on "sandbox". Guests can be CentOS 8S, Windows 11, Ubuntu 20, Debian whatever, Fedora 33 or 34, OpenWrt, etc. My question is this: what's best practices for making sure that a switch VLAN misconfiguration issue, a cabling to the wrong port, etc. doesn't compromise the KVM server itself? How do I allow my KVM server to *not* be on "external", but some of its guests to be, without compromising security? Being the paranoid sort, I'd like to use defense-in-depth so I'm not counting on any single step to protect me. For instance, I might use ebtables or iptables rules to block VLAN traffic on hosts/guests that I don't want to see certain VLAN's under any circumstances. But I might also add interfaces to the list of things that NetworkManager ignores as /etc/NetworkManager/NetworkManager.conf lines like: [keyfile] unmanaged-devices=interface-name:eno*,except:interface-name:eno1 unmanaged-devices=interface-name:enp* Thinking about that, I'm wondering what the notation is for telling NetworkManager to ignore all interfaces except those on VLAN 3, for instance. Would that be: unmanaged-devices=interface-name:eno*.*,except:interface-name:eno*.3 Or something else? And what else can I do to further secure my KVM host? I thought about using one untagged (non VLAN'd) Ethernet for the host, and another tagged Ethernet for the guests, but that just seemed like a false sense of security... Apologies for the cross posting... these questions seems to touch on iptables, libvirt, and NetworkManager all at the same time... Thanks, -Philip

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RE: apt libvirt package
by admin＠foundryserver.com 26 Oct '21

26 Oct '21

Hello again, So I have been struggling to compile the libvirt newest version 7.8.0. I am running CentOS 8 and during the meson build process I am getting non stop dependency fails. I keep installing the necessary packages and slowly progressing. Now the last one that stopped was gnutls. When I go to install that package via yum install gnutls -y it says that it is already complete and installed. Sigh... I am very surprised that there is no package for libvirt via rpm,yum etc. the lastest one installed via yum was 6.0.0. Can someone help by pointing to some where that has these latest packages? Or how best to compile this from source. It is amazing how much is missing from this distro. Thanks again. Brad From: admin(a)foundryserver.com <admin(a)foundryserver.com> Sent: October 23, 2021 12:54 PM To: 'libvirt-users(a)redhat.com' <libvirt-users(a)redhat.com> Subject: apt libvirt package Hello, I am new to kvm/qemu/libvirt. I am loving it. I am working on setting my first vm with shared file system with virtio-fs. I got an error, and google foo said, my version was too old. When I checked it said. libvirt version: 6.0.0, package: 0ubuntu8.14 (Matthew Ruffell matthew.ruffell(a)canonical.com <mailto:matthew.ruffell@canonical.com> Tue, 14 Sep 2021 14:00:49 +1200) I used apt package manager to install libvirt. I am running on ubuntu 20.04. I have tried apt update libvirt and I get..no updates available. What do I do at this point? Do I have to build it from source? Any help would be greatly appreciated. Brad

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how can i measure reliably the speed of a virtual disk ?
by Lentes, Bernd 25 Oct '21

25 Oct '21

Hi, we have some domains running on a two-node pacemaker cluster. The disks for the domains are raw files which reside on a SAN. I measured the speed of one domain inside the guest and got completely weird results: between 18MB/s and 750MB/s !?! I measured with hdparm -t. I think this is related because, from the host point of view, some data is on the disk and some data is on chache. The -t i used for hdparm does not influence the host, just the guest. Measures on the host give reliable and reasonable results about 350 MByte/s. How can i measure reliably the speed of a virtual disk ? Bernd -- Bernd Lentes System Administrator Institute for Metabolism and Cell Death (MCD) Building 25 - office 122 HelmholtzZentrum München bernd.lentes(a)helmholtz-muenchen.de phone: +49 89 3187 1241 phone: +49 89 3187 3827 fax: +49 89 3187 2294 http://www.helmholtz-muenchen.de/mcd Public key: 30 82 01 0a 02 82 01 01 00 b3 72 3e ce 2c 0a 6f 58 49 2c 92 23 c7 b9 c1 ff 6c 3a 53 be f7 9e e9 24 b7 49 fa 3c e8 de 28 85 2c d3 ed f7 70 03 3f 4d 82 fc cc 96 4f 18 27 1f df 25 b3 13 00 db 4b 1d ec 7f 1b cf f9 cd e8 5b 1f 11 b3 a7 48 f8 c8 37 ed 41 ff 18 9f d7 83 51 a9 bd 86 c2 32 b3 d6 2d 77 ff 32 83 92 67 9e ae ae 9c 99 ce 42 27 6f bf d8 c2 a1 54 fd 2b 6b 12 65 0e 8a 79 56 be 53 89 70 51 02 6a eb 76 b8 92 25 2d 88 aa 57 08 42 ef 57 fb fe 00 71 8e 90 ef b2 e3 22 f3 34 4f 7b f1 c4 b1 7c 2f 1d 6f bd c8 a6 a1 1f 25 f3 e4 4b 6a 23 d3 d2 fa 27 ae 97 80 a3 f0 5a c4 50 4a 45 e3 45 4d 82 9f 8b 87 90 d0 f9 92 2d a7 d2 67 53 e6 ae 1e 72 3e e9 e0 c9 d3 1c 23 e0 75 78 4a 45 60 94 f8 e3 03 0b 09 85 08 d0 6c f3 ff ce fa 50 25 d9 da 81 7b 2a dc 9e 28 8b 83 04 b4 0a 9f 37 b8 ac 58 f1 38 43 0e 72 af 02 03 01 00 01

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apt libvirt package
by admin＠foundryserver.com 23 Oct '21

23 Oct '21

Hello, I am new to kvm/qemu/libvirt. I am loving it. I am working on setting my first vm with shared file system with virtio-fs. I got an error, and google foo said, my version was too old. When I checked it said. libvirt version: 6.0.0, package: 0ubuntu8.14 (Matthew Ruffell matthew.ruffell(a)canonical.com <mailto:matthew.ruffell@canonical.com> Tue, 14 Sep 2021 14:00:49 +1200) I used apt package manager to install libvirt. I am running on ubuntu 20.04. I have tried apt update libvirt and I get..no updates available. What do I do at this point? Do I have to build it from source? Any help would be greatly appreciated. Brad

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load monitoring differences
by Marc 22 Oct '21

22 Oct '21

I was wondering if it is normal that the load reported from within the guest differs a lot from the guest load monitored on the host? Eg. currently I have guest that reports a load of 12-17 (uptime) while on the host top shows 70% cpu usage, I would expect this to be also around 12-17%.

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load monitoring differences
by Marc 22 Oct '21

22 Oct '21

I was wondering if it is normal that the load reported from within the guest differs a lot from the guest load monitored on the host? Eg. currently I have guest that reports a load of 12-17 (uptime) while on the host top shows 70% cpu usage, I would expect this to be also around 12-17%.

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