November 2024 - Users - libvirt List Archives

Running libvirt without dnsmasq
by procmem＠riseup.net 10 Dec '24

10 Dec '24

Hi, we are trying to document a way for our users to run libvirt without dnsmasq to reduce attack surface on the host. We are aware that the default network uses it but plan to disable that and use our own custom configured networks instead. Uninstalling dnsmasq causes libvirt to refuse to start even if the default network is no longer running. Is this possible or is this something that needs code changes upstream?

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Re: Set permissions and ownership of disk image created by vol-upload
by Martin Kletzander 26 Nov '24

26 Nov '24

On Tue, Nov 19, 2024 at 07:01:39PM +0000, Andrew Martin wrote: >Hello, > >I am using libvirt 8.0 on Ubuntu 22.04 and would like to utilize the vol-upload >command to upload a disk image: >https://www.libvirt.org/manpages/virsh.html#vol-upload > >I am using the "directory" storage pool type: >https://libvirt.org/storage.html#directory-pool > >However, when uploading the disk image, it gets written with octal permissions >0600 and owner root:root. Ideally I'd like this file to be owned by >libvirt-qemu:libvirt-qemu with permissions 0660 so that the group can read it. > >I've tried the following, none of which seem to alter the owner or permissions: > >- change the umask in the libvirtd systemd unit >- edit the user, group, and dynamic_ownership settings in /etc/libvirt/qemu.conf >- run "virsh pool-edit default" and change the <mode>, <owner>, or <group> tags > >How can I configure libvirtd to create these uploaded files with the desired >permissions and ownership? > Use virsh vol-create <pool> <volume.xml> where the volume xml looks something like this (adjust to your liking): <volume> <name>perms.img</name> <capacity unit='M'>100</capacity> <target> <path>/var/lib/libvirt/images/perms.img</path> <format type='raw'/> <permissions> <mode>0755</mode> <owner>77</owner> <group>77</group> </permissions> </target> </volume> And then use virsh vol-upload to populate the volume with what you want. That ought to be enough. HTH, Martin >Thanks, > >Andrew

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Help building .rpm of libvirt from fork
by Filippo Ferrando Damillano 25 Nov '24

25 Nov '24

Hi, i'm a CS Student who is trying to build a full rpm of libvirt out of a fork <https://gitlab.com/filippo-ferrando/libvirt-sd> because i need to add a scheduler to the libvirt configuration. I successfully builded the source code but i cannot manage to build a working .rpm executable, i'm using a Alma9 machine, and the original .spec file from the build of the repo. When i try to use rpmbuild, it goes until meson.build says that a file called `meson.build` is missing in the directory, even if the file itself exists. my fork is based on the master branch at tag 10.9.0 i'll include in the mail the log from meson and the spec file i'm using, thank to everyone for the help! -- ------------------------ Indirizzo istituzionale di posta elettronica degli studenti e dei laureati dell'Università di TorinoOfficial University of Turin email address for students and graduates

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ZFS storage backend
by Paul B. Henson 22 Nov '24

22 Nov '24

I'm running libvirt to manage virtual machines utilizing ZFS zvol's for storage. For organization and management purposes, these zvol's are nested: virt/qemu/debian12-template 15.8G 1.57T 24K none virt/qemu/debian12-template/bootefi 1.02G 1.57T 141M - virt/qemu/debian12-template/home 522M 1.57T 2.57M - virt/qemu/debian12-template/opt 522M 1.57T 3.00M - virt/qemu/debian12-template/root 8.13G 1.58T 970M - virt/qemu/debian12-template/swap 522M 1.57T 366M - virt/qemu/debian12-template/tmp 522M 1.57T 2.39M - virt/qemu/debian12-template/var 3.05G 1.57T 161M - virt/qemu/debian12-template/varlog 1.02G 1.57T 101M - virt/qemu/debian12-template/vartmp 522M 1.57T 3.75M - The libvirt ZFS integration seems to assume that all zvol's will exist at the top level of the pool, it won't let you create or manage a hierarchical structure. That is what it is, but it also then misrepresents the actual structure and shows things as being in the root when they are not: virsh # vol-list virt Name Path ------------------------------------- backup /dev/zvol/virt/backup boot-nb /dev/zvol/virt/boot-nb bootefi /dev/zvol/virt/bootefi dest /dev/zvol/virt/dest disk1 /dev/zvol/virt/disk1 home /dev/zvol/virt/home opt /dev/zvol/virt/opt root /dev/zvol/virt/root swap /dev/zvol/virt/swap tmp /dev/zvol/virt/tmp usr /dev/zvol/virt/usr usrlocal /dev/zvol/virt/usrlocal usrobj /dev/zvol/virt/usrobj usrports /dev/zvol/virt/usrports usrsrc /dev/zvol/virt/usrsrc var /dev/zvol/virt/var varlog /dev/zvol/virt/varlog vartmp /dev/zvol/virt/vartmp Ideally libvirt would support nested ZFS organizational structure, as that is a very common layout. But even if not, it probably shouldn't misrepresent a structure it doesn't understand? Thanks for any thoughts…

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network usually failing (nested virt, Debian)
by Misha Ramendik 21 Nov '24

21 Nov '24

Hello, I have a VPS where hardware nested virtualization is enabled, and I am trying to use this nested virtualization. The VPS runs Debian 12 and has 16 Gb of RAM. I installed libvirt/virt-manager/etc and downloaded the "nocloud" and "genericcloud" images from https://cdimage.debian.org/images/cloud/ . The description says that the "nocloud" image should allow passwordless root login but unfortunately it does not. I run things as root (this is a test setup) but I did chown all qcow images to "libvirt-qemu". I use the following command line: # virt-install --name test-cloud-vnc --os-variant debian11 --ram 8192 --disk debian-12-genericcloud-amd64.qcow2,device=disk,bus=virtio,size=10,format=qcow2 --hvm --import --noautoconsole --network default --graphics vnc,port=-1,listen=0.0.0.0 (Or the same for the nocloud image) The nocloud image sometimes, rarely, gets a DHCP lease (visible in "virsh net-dhcp-leases-default") and then responds to pings. But usually the nocloud image, and always the cloud image (but this might just be by random numbers), don't get a DHCP lease and cannot be pinged. This means that my attempt to set up cloud-init by an ad hoc webserver (as per https://cloudinit.readthedocs.io/en/latest/tutorial/qemu.html ) never got tested, because the cloud-init image can't access the network to start with. I did try --network default,model=e1000 - no change. I do successfully see the guest console when I connect to the VPS by VNC. Unfortunately, I don't have a password to log in with, so I can't even try to see whether it sees any network adapter. dmesg output for the time: [71382.495314] audit: type=1400 audit(1732157273.151:173): apparmor="STATUS" operation="profile_load" profile="unconfined" name="libvirt-3ca46e41-5cca-40b0-a5cd-d7d7e60de326" pid=30675 c omm="apparmor_parser" [71382.855419] audit: type=1400 audit(1732157273.511:174): apparmor="STATUS" operation="profile_replace" profile="unconfined" name="libvirt-3ca46e41-5cca-40b0-a5cd-d7d7e60de326" pid=3067 8 comm="apparmor_parser" [71383.228796] audit: type=1400 audit(1732157273.883:175): apparmor="STATUS" operation="profile_replace" profile="unconfined" name="libvirt-3ca46e41-5cca-40b0-a5cd-d7d7e60de326" pid=3068 2 comm="apparmor_parser" [71383.626483] audit: type=1400 audit(1732157274.279:176): apparmor="STATUS" operation="profile_replace" info="same as current profile, skipping" profile="unconfined" name="libvirt-3ca46 e41-5cca-40b0-a5cd-d7d7e60de326" pid=30686 comm="apparmor_parser" [71383.664542] virbr0: port 1(vnet0) entered blocking state [71383.667108] virbr0: port 1(vnet0) entered disabled state [71383.671212] device vnet0 entered promiscuous mode [71383.674775] virbr0: port 1(vnet0) entered blocking state [71383.677431] virbr0: port 1(vnet0) entered listening state [71384.077738] audit: type=1400 audit(1732157274.731:177): apparmor="STATUS" operation="profile_replace" profile="unconfined" name="libvirt-3ca46e41-5cca-40b0-a5cd-d7d7e60de326" pid=3069 7 comm="apparmor_parser" [71385.702614] virbr0: port 1(vnet0) entered learning state [71387.718555] virbr0: port 1(vnet0) entered forwarding state [71387.720995] virbr0: topology change detected, propagating I tried to boot the GRML ISO ( https://grml.org/ ) using the following command: # virt-install --name test-cloud-vnc --os-variant debian11 --ram 8192 --disk debian-12-genericcloud-amd64.qcow2,device=disk,bus=virtio,size=10,format=qcow2 --hvm --import --noautoconsole --network default --cdrom grml64-full_2024.02.iso --boot cdrom --graphics vnc,port=-1,listen=0.0.0.0 Unfortunately, the GRML boot hangs shortly after starting, apparently while trying to load the initrd. So I can't poke around in the guest in this way, either. Advice about debugging this would be highly appreciated. -- Yours, Misha Ramendik Unless explicitly stated, all opinions in my mail are my own and do not reflect the views of any organization

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Set permissions and ownership of disk image created by vol-upload
by Andrew Martin 19 Nov '24

19 Nov '24

Hello, I am using libvirt 8.0 on Ubuntu 22.04 and would like to utilize the vol-upload command to upload a disk image: https://www.libvirt.org/manpages/virsh.html#vol-upload I am using the "directory" storage pool type: https://libvirt.org/storage.html#directory-pool However, when uploading the disk image, it gets written with octal permissions 0600 and owner root:root. Ideally I'd like this file to be owned by libvirt-qemu:libvirt-qemu with permissions 0660 so that the group can read it. I've tried the following, none of which seem to alter the owner or permissions: - change the umask in the libvirtd systemd unit - edit the user, group, and dynamic_ownership settings in /etc/libvirt/qemu.conf - run "virsh pool-edit default" and change the <mode>, <owner>, or <group> tags How can I configure libvirtd to create these uploaded files with the desired permissions and ownership? Thanks, Andrew

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Immediate "system reset" when booting UEFI?
by Lars Kellogg-Stedman 18 Nov '24

18 Nov '24

Hey folks, I'm running libvirt 10.1.0/qemu-system-x86-core-9.0.1-1.fc40.x86_64 on Fedora 40. I'm trying to boot an Ubuntu image in UEFI mode, like this: virt-install -r 2048 -n ubuntu.virt --os-variant ubuntu24.04 \ --disk pool=default,size=10,backing_store=mantic-server-cloudimg-amd64.img,backing_format=qcow2 \ --cloud-init root-ssh-key=$HOME/.ssh/id_ed25519.pub \ --boot uefi This results in the domain booting up and then immediately resetting: BdsDxe: loading Boot0001 "UEFI Misc Device" from PciRoot(0x0)/Pci(0x2,0x3)/Pci(0x0,0x0) BdsDxe: starting Boot0001 "UEFI Misc Device" from PciRoot(0x0)/Pci(0x2,0x3)/Pci(0x0,0x0) Reset System Domain creation completed. At this point, the machine is actually powered down and needs to be restarted manually: virsh start ubuntu.virt This works fine, and the domain boots successfully, but now the cloud-init metadata provided by the `--cloud-init` option to `virt-install` is no longer available (because this is no longer the initial, virt-install managed boot of the domain). What is causing the firmware to reset the system when it first boots? -- Lars Kellogg-Stedman <lars(a)redhat.com>

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hard-disk via virtio-blk under windows (discard_granularity=0)
by d tbsky 18 Nov '24

18 Nov '24

Hi: few years ago virtio-blk device was showing as hard-disk under windows. recent years the driver change the device to show as thin-provisioned disk. the change is good for ssd, but not so good for raw hard-disk. under windows server 2022 the default virtio-blk situation is quite bad, ssd trim is very slow. and defrag a bigger volume like 1TB harddisk will always show "memory not enough", even when the volume is empty. I found discussions to change the "discard_granularity" to make trim happy again. and libvirt support the syntax like below: <blockio discard_granularity='2097152'/> I also found if I can set "discard_granularity" to zero, then windows will recognize the device as "traditional hard drive" again and won't do unnecessary trim to it. I want to do this for years, but couldn't find a way to set it up like vitio-scsi's rotational parameter. the sad part is if I setup it under RHEL 9.4 with librirt 10.0 like below: <blockio discard_granularity='0'/> the line will just disappear when I close "virsh edit" so I can only use complex format with "<qemu:override>" to set "discard_granularity='0'" I wonder if libvirt would be changed to accept "discard_granularity='0'" so the traditional hard-disk can be recognized under windows again. or is there better ways to distinguish hard-disk/ssd/thin-disk for virtio-blk now? Regards, tbskyd

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[FOSDEM] Reminder about call for participation - Virtualization and Cloud infrastructure Room 2025
by Piotr Kliczewski 17 Nov '24

17 Nov '24

All, This yeah submission deadline is enforced for all devrooms so this year our due date is on 1st of December not as all previous years on 8th. This is our gentle reminder to submit [0] your proposals. See you soon at FOSDEM! [0] https://fosdem.org/submit

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error: unsupported flags (0x4) in function virStorageVolDefParseXML
by Veiko Kukk 08 Nov '24

08 Nov '24

Hi! Simple volume definition: <volume type='file'> <name>tstlog01-system</name> <capacity unit='GiB'>20</capacity> <target> <compat>1.1</compat> <format type='qcow2'/> </target> </volume> # virsh vol-create --pool libvirt-ssd0 --file vm-files/tstlog01/tstlog01-sys tem-vol.xml --validate error: Failed to create vol from vm-files/tstlog01/tstlog01-system-vol.xml error: unsupported flags (0x4) in function virStorageVolDefParseXML Omitting --validate creates volume # virsh vol-dumpxml --pool libvirt-ssd0 --vol tstlog01-system <volume type='file'> <name>tstlog01-system</name> <key>/var/lib/libvirt/images/tstlog01-system</key> <capacity unit='bytes'>21474836480</capacity> <allocation unit='bytes'>200704</allocation> <physical unit='bytes'>196928</physical> <target> <path>/var/lib/libvirt/images/tstlog01-system</path> <format type='qcow2'/> <permissions> <mode>0600</mode> <owner>0</owner> <group>0</group> <label>system_u:object_r:virt_image_t:s0</label> </permissions> <timestamps> <atime>1730277533.331347844</atime> <mtime>1730277533.329347839</mtime> <ctime>1730277533.330347841</ctime> <btime>0</btime> </timestamps> </target> </volume> # file /var/lib/libvirt/images/tstlog01-system /var/lib/libvirt/images/tstlog01-system: QEMU QCOW2 Image (v2), 21474836480 bytes # virsh vol-create-as libvirt-ssd0 tstlog01-system 20g --format qcow2 Vol tstlog01-system created # virsh vol-dumpxml --pool libvirt-ssd0 --vol tstlog01-system <volume type='file'> <name>tstlog01-system</name> <key>/var/lib/libvirt/images/tstlog01-system</key> <capacity unit='bytes'>21474836480</capacity> <allocation unit='bytes'>200704</allocation> <physical unit='bytes'>196928</physical> <target> <path>/var/lib/libvirt/images/tstlog01-system</path> <format type='qcow2'/> <permissions> <mode>0600</mode> <owner>0</owner> <group>0</group> <label>system_u:object_r:virt_image_t:s0</label> </permissions> <timestamps> <atime>1730277391.657950326</atime> <mtime>1730277391.656950323</mtime> <ctime>1730277391.657950326</ctime> <btime>0</btime> </timestamps> </target> </volume> It seems both volumes are identical - the one created without --validate and the one created with vol-create-as. Questions: 1) Why does validation fail? How to debug it? 2) Why doesn't libvirt create qcow2 v3 even when specifying compat 1.1? When creating an image using virt-manager on the same libvirt hypervisor host, v3 images are created. Alma Linux 9.4, libvirt-10.0.0-6.7.el9_4.alma.1.x86_64, qemu-kvm-8.2.0-11.el9_4.6.x86_64 With best regards, Veiko

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