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Re: domain not getting IP address
by Pavel Mores 22 Sep '25

22 Sep '25

On Thu, Sep 18, 2025 at 11:29 AM Pavel Mores <pmores(a)redhat.com> wrote: > On Thu, Sep 18, 2025 at 10:25 AM Martin Kletzander <mkletzan(a)redhat.com> > wrote: > >> On Wed, Sep 17, 2025 at 04:02:12PM +0200, Pavel Mores wrote: >> >On Wed, Sep 17, 2025 at 3:05 PM Martin Kletzander <mkletzan(a)redhat.com> >> >wrote: >> > >> >> On Wed, Sep 17, 2025 at 02:14:51PM +0200, Pavel Mores via Users wrote: >> >> >Hi, >> >> > >> >> >I'm examining a domain that's connected to the 'default' network >> >> > >> >> ># virsh net-dumpxml default >> >> ><network connections='1'> >> >> > <name>default</name> >> >> > <uuid>c757baa7-2b31-4794-9dfb-0df384575602</uuid> >> >> > <forward mode='nat'> >> >> > <nat> >> >> > <port start='1024' end='65535'/> >> >> > </nat> >> >> > </forward> >> >> > <bridge name='virbr0' stp='on' delay='0'/> >> >> > <mac address='52:54:00:37:b7:92'/> >> >> > <ip address='192.168.122.1' netmask='255.255.255.0'> >> >> > <dhcp> >> >> > <range start='192.168.122.2' end='192.168.122.254'/> >> >> > </dhcp> >> >> > </ip> >> >> ></network> >> >> > >> >> >> >> This is standard. >> >> >> >> >using a device as follows: >> >> > >> >> ><interface type='network'> >> >> > <mac address='52:54:00:ed:06:2e'/> >> >> > <source network='default' >> portid='83db8ca9-baed-47f3-ba0d-1a967ee86aa5' >> >> >bridge='virbr0'/> >> >> > <target dev='vnet19'/> >> >> > <model type='virtio'/> >> >> > <alias name='net0'/> >> >> > <address type='pci' domain='0x0000' bus='0x00' slot='0x02' >> >> >function='0x0'/> >> >> ></interface> >> >> > >> >> >> >> This looks fine. >> >> >> >> >The domain is running but apparently without an IP address: >> >> > >> >> ># virsh domifaddr podvm-podsandbox-totok-8f10756a >> >> > Name MAC address Protocol Address >> >> >> >> >> >------------------------------------------------------------------------------- >> >> > >> >> >> >> This shows that libvirt does not know about any IP address. Does >> adding >> >> "--source agent", "--source arp" or "--source lease" change anything? >> >> >> > >> >'arp' and 'lease' don't but >> > >> ># virsh domifaddr --source agent podvm-podsandbox-totok-8f10756a >> >error: Failed to query for interfaces addresses >> >error: argument unsupported: QEMU guest agent is not configured >> > >> >This is surprising to me since this is a peer pods setup where the domain >> >in question is a podvm running an image which I was told does have >> >the qemu agent running. >> > >> >However the agent shouldn't be necessary for IP address acquisition I >> guess, >> >right? >> > >> >>The requisite host-side interfaces look good (to me anyway :-)): >> >> > >> >> >10: virbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc htb >> state UP >> >> >group default qlen 1000 >> >> > link/ether 52:54:00:37:b7:92 brd ff:ff:ff:ff:ff:ff >> >> > inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0 >> >> > valid_lft forever preferred_lft forever >> >> >[...] >> >> >35: vnet19: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue >> >> master >> >> >virbr0 state UNKNOWN group default qlen 1000 >> >> > link/ether fe:54:00:ed:06:2e brd ff:ff:ff:ff:ff:ff >> >> > inet6 fe80::fc54:ff:feed:62e/64 scope link proto kernel_ll >> >> > valid_lft forever preferred_lft forever >> >> > >> >> >I can share more information about the setup if necessary but I'll >> stop >> >> >here for now since I feel this must be just a simple stupid oversight >> on >> >> my >> >> >part. Please let me know if you'd like to have additional info. >> >> > >> >> >> >> When this happens to me sometimes, it's most often a firewall issue and >> >> the VM does not get any IP address or cannot communicate outside its >> >> network. >> >> >> > >> >I've seen a firewall suggested as a possible culprit, yes, however I >> don't >> >quite >> >know what it should look like. iptables appear unconfigured: >> > >> ># iptables -L -v -n >> >Chain INPUT (policy ACCEPT 0 packets, 0 bytes) >> > pkts bytes target prot opt in out source >> >destination >> > >> >Chain FORWARD (policy ACCEPT 0 packets, 0 bytes) >> > pkts bytes target prot opt in out source >> >destination >> > >> >Chain OUTPUT (policy ACCEPT 0 packets, 0 bytes) >> > pkts bytes target prot opt in out source >> >destination >> > >> >`nft list ruleset` lists only rules that look managed by libvirt >> >itself(*). At any >> >rate the host machine has no specific hand-configured firewall that I >> know >> >of. >> > >> > >> >> What it can be here is that there are some access issues to the dnsmasq >> >> lease file. >> >> >> >> What's in your /var/lib/libvirt/dnsmasq/virbr0.status file on the host? >> >> >> > >> >It's empty. >> > >> >Thanks Martin! >> >pvl >> > >> >(*) # nft list ruleset >> >table ip libvirt_network { >> >chain forward { >> >type filter hook forward priority filter; policy accept; >> >counter packets 85854914 bytes 398726525237 jump guest_cross >> >counter packets 85854914 bytes 398726525237 jump guest_input >> >counter packets 34777368 bytes 3386943972 jump guest_output >> >} >> > >> >chain guest_output { >> >ip saddr 192.168.122.0/24 iif "virbr0" counter packets 0 bytes 0 accept >> >> This suggests there were no incoming packets from an IP address in the >> range on the bridge. >> >> >iif "virbr0" counter packets 0 bytes 0 reject >> >> And no packets from outside of that range that would fall through to >> this above rule. >> >> [...] >> >> >} >> > >> >chain guest_input { >> >> [...] >> >> >oif "virbr0" ip daddr 192.168.122.0/24 ct state established,related >> counter >> >packets 0 bytes 0 accept >> >> No packets sent to the address range on the bridge, but >> >> >oif "virbr0" counter packets 0 bytes 0 reject >> >> basically no packets sent at all. >> >> >} >> > >> >chain guest_cross { >> >iif "openshift-412" oif "openshift-412" counter packets 0 bytes 0 accept >> >iif "openshift-419" oif "openshift-419" counter packets 0 bytes 0 accept >> >iif "openshift-416" oif "openshift-416" counter packets 0 bytes 0 accept >> >iif "openshift-415" oif "openshift-415" counter packets 0 bytes 0 accept >> >iif "openshift-413" oif "openshift-413" counter packets 0 bytes 0 accept >> >iif "virbr0" oif "virbr0" counter packets 0 bytes 0 accept >> >> No intra-network communication >> >> [...] >> >> >chain guest_nat { >> >type nat hook postrouting priority srcnat; policy accept; >> >> [...] >> >> >ip saddr 192.168.122.0/24 ip daddr 224.0.0.0/24 counter packets 50 bytes >> >3676 return >> >> There were some IPv4 multicast packets, but these could've originated >> from the host. >> >> >ip saddr 192.168.122.0/24 ip daddr 255.255.255.255 counter packets 0 >> bytes >> >0 return >> >> And no broadcast packets from the address space. >> >> >meta l4proto tcp ip saddr 192.168.122.0/24 ip daddr != 192.168.122.0/24 >> >counter packets 0 bytes 0 masquerade to :1024-65535 >> >meta l4proto udp ip saddr 192.168.122.0/24 ip daddr != 192.168.122.0/24 >> >counter packets 0 bytes 0 masquerade to :1024-65535 >> >ip saddr 192.168.122.0/24 ip daddr != 192.168.122.0/24 counter packets 0 >> >bytes 0 masquerade >> >> No NAT, anything. >> >> [...] >> >ip saddr 192.168.14.0/24 ip daddr 224.0.0.0/24 counter packets 50 bytes >> >3675 return >> >> These counters on another range are the same, so I would say all the >> multicast packets on the range we are interested in are just the same, >> hence having nothing to do with the guest. >> >> >} >> >} >> >table ip6 libvirt_network { >> >chain forward { >> >type filter hook forward priority filter; policy accept; >> >counter packets 0 bytes 0 jump guest_cross >> >counter packets 0 bytes 0 jump guest_input >> >counter packets 0 bytes 0 jump guest_output >> >> And totally nothing with IPv6. >> > > As a bit of context, this is a virtlab machine whose primary purpose is to > run > kcli-based openshift clusters whose nodes are libvirt domains. Those are > the > "openshift-41[1-9]" networks and bridges. They are unrelated to the setup > I'm > looking into and most of them are actually obsolete (it's been years now > since > a 4.11 cluster last ran on the host :-)). > > My "guess" would be that the guest did not even get an IP address, maybe >> did not eve try DHCP. Are you sure the guest booted? >> > > I think it is, based on > > # virsh list > Id Name State > ------------------------------------------------- > [...] > 20 podvm-podsandbox-totok-8f10756a running > > But now that you mention it, I'm not positively sure that it tried DHCP. > The zero > traffic on the virbr0 bridge you mention above is overall explainable by > the domain > not having an address *but* if it did try DHCP those packets would show up > in the > virbr0 stats I guess? > > I did check out previously the DHCP leases on the 'default' network: > > # virsh net-dhcp-leases default > Expiry Time MAC address Protocol IP address Hostname Client ID > or DUID > > ----------------------------------------------------------------------------------- > > and there are none but that doesn't rule out any other failure in DHCP. > > The domain runs a peer pods podvm image which I don't have any control > over and > frankly am not familiar with. I assume that it does do DHCP to configure > its interfaces > but as the guest agent example shows my information about the image might > not be > always accurate. > I verified that the VM does do DHCP (there actually doesn't seem to be any other means for a podvm to get its network configured in peer pods). pvl > Is there a way to check if the domain attempts DHCP purely from the > libvirt side, just > using libvirt means? > > Thanks! > pvl >

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domain not getting IP address
by Pavel Mores 18 Sep '25

18 Sep '25

Hi, I'm examining a domain that's connected to the 'default' network # virsh net-dumpxml default <network connections='1'> <name>default</name> <uuid>c757baa7-2b31-4794-9dfb-0df384575602</uuid> <forward mode='nat'> <nat> <port start='1024' end='65535'/> </nat> </forward> <bridge name='virbr0' stp='on' delay='0'/> <mac address='52:54:00:37:b7:92'/> <ip address='192.168.122.1' netmask='255.255.255.0'> <dhcp> <range start='192.168.122.2' end='192.168.122.254'/> </dhcp> </ip> </network> using a device as follows: <interface type='network'> <mac address='52:54:00:ed:06:2e'/> <source network='default' portid='83db8ca9-baed-47f3-ba0d-1a967ee86aa5' bridge='virbr0'/> <target dev='vnet19'/> <model type='virtio'/> <alias name='net0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/> </interface> The domain is running but apparently without an IP address: # virsh domifaddr podvm-podsandbox-totok-8f10756a Name MAC address Protocol Address ------------------------------------------------------------------------------- The requisite host-side interfaces look good (to me anyway :-)): 10: virbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc htb state UP group default qlen 1000 link/ether 52:54:00:37:b7:92 brd ff:ff:ff:ff:ff:ff inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0 valid_lft forever preferred_lft forever [...] 35: vnet19: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master virbr0 state UNKNOWN group default qlen 1000 link/ether fe:54:00:ed:06:2e brd ff:ff:ff:ff:ff:ff inet6 fe80::fc54:ff:feed:62e/64 scope link proto kernel_ll valid_lft forever preferred_lft forever I can share more information about the setup if necessary but I'll stop here for now since I feel this must be just a simple stupid oversight on my part. Please let me know if you'd like to have additional info. Thanks in advance, pvl

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How to recover from "Display output is not active"
by Jeffrey Walton 11 Sep '25

11 Sep '25

Hi Everyone, I'm working on Ubuntu 22.04.5, amd64, fully patched. It provides QEMU 1:6.2+dfsg-2ubuntu6.26 and libvirt 8.0.0-1ubuntu7.11. The problem I am experiencing is, when the host machine blanks the monitor, I lose the display on the guest when I sit back down at the computer and wake the monitor. The error message (?) in the guest window is, "Display output is not active." The condition happens with both VIRTIO and VGA models. Also see <https://imgur.com/a/tEp73k2>. I have not found a workaround to stop it from happening or recover after it happens. I have to Force Off the VM and then restart the VM to the display back. My host power configuration is: disable sleep, suspend, hibernate and hybrid-sleep via systemd's systemctl. However, I allow the monitor to be turned off after 15 minutes of inactivity. My guest power configuration is whatever the distro provides. Based on my searching, others have experienced the problem. And one fellow says switching to the VGA model fixed it for him. (But no joy for me). Does anyone have any suggestions for a work around? Thanks in advance. (And my apologies if this is the wrong list). Jeff

2 5

QNAP backup of virsh virtual machines and NFS shared drives for Plex, Subversion, Mailbox to OneDrive via rclone
by pjbondi＠systemdatabase.com 10 Sep '25

10 Sep '25

Hello virsh community. https://community.qnap.com/t/qnap-backup-of-virsh-virtual-machines-and-nfs-… Thank you so much for your help with my online virsh backup script. I've posted my script at the above address. I hope it helps someone protect their data. In my opinion, the script is an excellent implementation of --> https://libvirt.org/kbase/live_full_disk_backup.html https://www.worldbackupday.com/en

1 0

List checkpoints
by francisco.garcia＠baculasystems.com 09 Sep '25

09 Sep '25

Hello, I'm using checkpoints to back up Libvirt domains. I'm using the "virsh backup-begin" tool and specifying the dombackup and checkpoint XML files. Everything works correctly (I perform full and incremental backups) without any issues. When I list the checkpoints using the "virsh checkpoint-list DOMAIN --parent --topological" tool, it correctly shows me the entire chain of full and incremental backups. However, when I perform a differential backup, setting the parent of that checkpoint to the last full checkpoint, I have problems when listing them. It tells me that the parent of the differential checkpoint is the last incremental checkpoint, instead of the full checkpoint. And I don't understand why, because when I perform the backup-begin, I specify the full checkpoint in the "incremental" label, and the bitmap generated from the disk is all the data from the full checkpoint on. I put the xmls that I used: FULL BACKUP: dombackup.xml: ``` <?xml version="1.0" encoding="UTF-8" standalone="yes"?> <domainbackup mode="pull"> <server name="localhost" port="10809"/> <disks> <disk name="vda" type="file"> <scratch file="/tmp/libvirt-full-30-vda-debian12.scratch"/> </disk> <disk name="vdb" type="file"> <scratch file="/tmp/libvirt-full-30-vdb-debian12.scratch"/> </disk> </disks> </domainbackup> ``` checkpoint.xml ``` <?xml version="1.0" encoding="UTF-8" standalone="yes"?> <domaincheckpoint> <name>Full-30-Debian12</name> <disks> <disk name="vda" bitmap="Full-30-Debian12" checkpoint="bitmap"/> <disk name="vdb" bitmap="Full-30-Debian12" checkpoint="bitmap"/> <disk name="sda" checkpoint="no"/> </disks> </domaincheckpoint> ``` -------------------------------------------------------- INCREMENTAL BACKUP: dombackup.xml ``` <?xml version="1.0" encoding="UTF-8" standalone="yes"?> <domainbackup mode="pull"> <server name="localhost" port="10809"/> <incremental>Full-30-Debian12</incremental> <disks> <disk name="vda" type="file"> <scratch file="/tmp/libvirt-incremental-35-vda-debian12.scratch"/> </disk> <disk name="vdb" type="file"> <scratch file="/tmp/libvirt-incremental-35-vdb-debian12.scratch"/> </disk> </disks> </domainbackup> ``` checkpoint.xml ``` <?xml version="1.0" encoding="UTF-8" standalone="yes"?> <domaincheckpoint> <name>Incremental-31-Debian12</name> <parent> <name>Full-30-Debian12</name> </parent> <disks> <disk name="vda" bitmap="Incremental-31-Debian12" checkpoint="bitmap"/> <disk name="vdb" bitmap="Incremental-31-Debian12" checkpoint="bitmap"/> <disk name="sda" checkpoint="no"/> </disks> </domaincheckpoint> ``` ----------------------------------------------------------------- DIFFERENTIAL BACKUP: dombackup.xml ``` <?xml version="1.0" encoding="UTF-8" standalone="yes"?> <domainbackup mode="pull"> <server name="localhost" port="10809"/> <incremental>Full-30-Debian12</incremental> <disks> <disk name="vda" type="file"> <scratch file="/tmp/libvirt-differential-36-vda-debian12.scratch"/> </disk> <disk name="vdb" type="file"> <scratch file="/tmp/libvirt-differential-36-vdb-debian12.scratch"/> </disk> </disks> </domainbackup> ``` checkpoint.xml ``` <?xml version="1.0" encoding="UTF-8" standalone="yes"?> <domaincheckpoint> <name>Differential-32-Debian12</name> <parent> <name>Full-30-Debian12</name> </parent> <disks> <disk name="vda" bitmap="Differential-32-Debian12" checkpoint="bitmap"/> <disk name="vdb" bitmap="Differential-32-Debian12" checkpoint="bitmap"/> <disk name="sda" checkpoint="no"/> </disks> </domaincheckpoint> ``` ----------------------------------------------------------------------- After apply several "virsh backup-begin" with these files: ``` virsh checkpoint-list debian12 --topological --parent Name Creation Time Parent -------------------------------------------------------------------------------------------------------------------------------- Full-30-Debian12 2025-07-09 17:08:31 +0200 Incremental-31-Debian12 2025-07-09 17:34:56 +0200 Full-30-Debian12 Differential-32-Debian12 2025-07-09 17:37:51 +0200 Incremental-31-Debian12 ``` I do not know why the parent of "Differential-32-Debian12" is "Incremental-31-Debian12" instead of "Full-30-Debian12". Any ideas?

2 1

Co-stop with non-VMware virtualization?
by Troels Arvin 08 Sep '25

08 Sep '25

Hello, How important is it to consider "co-stop" with non-VMWare virtualization such as KVM? I haven't been able to find anything about this for KVM, but there's some material about it for VMWare (albeit typically rather old material). Based on VMWare material, by "co-stop" I mean the following situation: A VM called "x" has been assigned quite a few vCPUs, e.g. 10, on a hypervisor with e.g. 20 physical cores. The hypervisor is hosting many other VMs, and the many VMs take turn running on the hardware. Now, if it's often the case that, e.g., only 7 physical threads are available when it's x's turn to run, the hypervisor needs to postpone running x till all 10 cores can be allocated at the same time. During this waiting time, x is stopped (co-stop). Is my understanding correct? Or will KVM allow x to run on (e.g.) 7 cores, even though the VM thinks it has 10 vCPUs available? It's my understanding that with KVM, the co-stopped situation is reflected in the VM's "steal time" metric in a tool like "top". Does hyperthreading in either the hypervisor and/or the guest impact the risk of co-stop? -- Regards, Troels Arvin

2 1

purge question about https://libvirt.org/kbase/live_full_disk_backup.html
by Philip Bondi 27 Aug '25

27 Aug '25

Hello libvirt users: On QNAP platform, this is my outcome from the following step "2. Enumerate the current block device(s) in use, again. Notice that the current disk image in use is the above-created overlay, overlay1.qcow2:" I'm showing both pre- and post-execution from the shell. There's 2 files. Should both files be purged according to the instruction "Now you can safely discard the overlay image"? + virsh domblklist 9c7d2c4d-9c28-44bd-8da9-642a63b25c39 Target Source ------------------------------------------------------------------------------- vda /share/Virtual-Machines/SHACKLETON1210/SHACKLETON1210_00.1755932401 hda /share/Virtual-Machines/debian-12.10.0-amd64-netinst.iso ls -alF /share/CACHEDEV2_DATA/Virtual-Machines/SHACKLETON1210/SHACKLETON1210_00.1755932401* -rw-r--r-- 1 admin administrators 177602560 2025-08-23 05:02 SHACKLETON1210_00.1755932401 -rw------- 1 admin administrators 40470118400 2025-08-23 03:42 SHACKLETON1210_00.1755932401.1755934525

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issue running SEV-SNP VM via virt-install
by sven.springer＠cloudandheat.com 26 Aug '25

26 Aug '25

Hi, I am a bit lost in which parameters I need to provide to virt-install to successfully launch an SEV-SNP capable VM. I already managed to start an SEV and SEV-ES VM via virt-install, and was also able to start an SEV-SNP VM via qemu-system-x86_64 directly. So what I am stuck with is this error message: ERROR internal error: QEMU unexpectedly closed the monitor (vm='debian-vm-1'): 2025-08-22T17:26:25.863482Z qemu-system-x86_64: pflash with kvm requires KVM readonly memory support when using this or variants of this command: virt-install \ --name "$VM_NAME" \ --noautoconsole \ --graphics none \ --import \ --memory 3072 \ --vcpus 2 \ --os-variant "$OS_VARIANT" \ --network network=default,model=virtio \ --memtune hard_limit=3407872 \ --qemu-commandline='-append "root=/dev/vda1 console=ttyS0"' \ --machine confidential-guest-support=sev0,memory-backend=ram1 \ --machine=q35 \ --boot uefi,loader=/usr/share/ovmf/OVMF.amdsev.fd,loader.stateless=yes,loader.secure=no,loader.type=pflash,kernel="$VMLINUZ",initrd="$INITRD" \ --qemu-commandline='-object memory-backend-memfd,id=ram1,size=8G,share=true,prealloc=false' \ --disk bus=virtio,path="$OVERLAY_IMG",format=qcow2 \ --cloud-init user-data="$USER_DATA" \ --virt-type kvm \ --launchSecurity sev-snp,policy=0x30000,cbitpos=51,reducedPhysBits=1,kernelHashes=on \ --cpu host-passthrough \ The issue is not with the images, since with the same ones it works when going directly via qemu-system-x86_64. I notice that libvirt is converting the --boot line to -blockdev, instead of -bios which seems to be the way to go according to https://bugs.launchpad.net/ubuntu/+source/edk2/+bug/2106771 , so I tried something like --qemu-commandline='-bios /usr/share/ovmf/OVMF.amdsev.fd -kernel "$VMLINUZ"' \ but to no avail. Did anyone manage to run a SEV-SNP VM via virt-install, or even just a libvirt-xml ? I would appreciate any tips or working xml or cli call.

2 3

purge question about https://libvirt.org/kbase/live_full_disk_backup.html
by pjbondi＠systemdatabase.com 25 Aug '25

25 Aug '25

Hello libvirt users: On QNAP, this is my outcome from the following step "2. Enumerate the current block device(s) in use, again. Notice that the current disk image in use is the above-created overlay, overlay1.qcow2:" I'm showing both pre- and post-execution from the shell. There's 2 files. Should both files be purged according to the instruction "Now you can safely discard the overlay image"? + virsh domblklist 9c7d2c4d-9c28-44bd-8da9-642a63b25c39 Target Source ------------------------------------------------------------------------------- vda /share/Virtual-Machines/SHACKLETON1210/SHACKLETON1210_00.1755932401 hda /share/Virtual-Machines/debian-12.10.0-amd64-netinst.iso ls -alF /share/CACHEDEV2_DATA/Virtual-Machines/SHACKLETON1210/SHACKLETON1210_00.1755932401* -rw-r--r-- 1 admin administrators 177602560 2025-08-23 05:02 SHACKLETON1210_00.1755932401 -rw------- 1 admin administrators 40470118400 2025-08-23 03:42 SHACKLETON1210_00.1755932401.1755934525

1 0

FYI: Planned list outage Mon 25th Aug from 10:00 JST
by Daniel P. Berrangé 20 Aug '25

20 Aug '25

We have a planned outage of the libvirt.org mailing lists on Monday 25th August. The outage is anticipated to begin at approx 10:00 JST (Japan), and all going well, should last no more than a couple hours. There will be various cosmetic changes to the lists.libvirt.org web interface after the upgrade, due to the newer software versions introduced. With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|

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Re: Clarification Needed: virsh snapshot-delete Behavior with External Snapshots (--disk-only)
by Peter Krempa 25 Jul '25

25 Jul '25

On Wed, Jul 23, 2025 at 04:57:57 +0000, P, Rajasekar via Users wrote: > Hello libvirt community, > > I am seeking clarification on the behavior of `virsh snapshot-delete` when used with external snapshots (created with the `--disk-only` option). > > **Environment:** > - libvirt version: 10.5.0 Note that this was released almost a year ago. > - Kernel version: 5.14.0-503.22.1.el9_5.x86_64 > - Disk image format: qcow2 > - Host OS: RHEL 9.5 > > **Steps to reproduce:** > 1. Create an external snapshot: > virsh snapshot-create-as --domain <vm> --name snap1 --disk-only --atomic > 2. Delete the snapshot: > virsh snapshot-delete <vm> --snapshotname snap1 > > **Observed behavior:** > - Changes from the overlay (snapshot) file are merged into the base image. > - The snapshot metadata is removed from libvirt. > - The snapshot file remains on disk (appears orphaned). You mean that the original overlay images remained on disk? e.g. /path/to/originalimage.snap1 ? > **Questions:** > - Is the observed automatic merge of the overlay file into the base image during `snapshot-delete` the intended behavior for external snapshots in recent libvirt versions? Or we need separate `blockcommit` step. Yes it is intended, because deleting a snapshot is effectively meaning "I don't want to return to this point any more" so the extra overlay makes no sense. > - Should the snapshot file be deleted automatically, or is manual cleanup required? If you mean the overlay, then yes it should have been deleted. > - Is there any official documentation that clarifies this behavior for external snapshots, as most documentation seems to focus on internal snapshots? The semantics of external and internal snapshots are supposed to be indentical. I don't think we document to a deep extent the actual behaviour WRT to the disk files.

1 0

Clarification Needed: virsh snapshot-delete Behavior with External Snapshots (--disk-only)
by P, Rajasekar 23 Jul '25

23 Jul '25

Hello libvirt community, I am seeking clarification on the behavior of `virsh snapshot-delete` when used with external snapshots (created with the `--disk-only` option). **Environment:** - libvirt version: 10.5.0 - Kernel version: 5.14.0-503.22.1.el9_5.x86_64 - Disk image format: qcow2 - Host OS: RHEL 9.5 **Steps to reproduce:** 1. Create an external snapshot: virsh snapshot-create-as --domain <vm> --name snap1 --disk-only --atomic 2. Delete the snapshot: virsh snapshot-delete <vm> --snapshotname snap1 **Observed behavior:** - Changes from the overlay (snapshot) file are merged into the base image. - The snapshot metadata is removed from libvirt. - The snapshot file remains on disk (appears orphaned). **Questions:** - Is the observed automatic merge of the overlay file into the base image during `snapshot-delete` the intended behavior for external snapshots in recent libvirt versions? Or we need separate `blockcommit` step. - Should the snapshot file be deleted automatically, or is manual cleanup required? - Is there any official documentation that clarifies this behavior for external snapshots, as most documentation seems to focus on internal snapshots? Thank you for your help and clarification! Best regards, Raj.

1 0

Hanging migration leaving domain in paused state
by Yangchen Ye 21 Jul '25

21 Jul '25

Hi, We are running libvirt 8.0.0, and sometimes live migration could not finish (because the guest is dirtying the memory too fast). We implemented a monitor that increases max downtime when it observed that "Data Remaining" bumps up. But we found a strange sequence of events from the monitor, which leads to a paused domain on the destination hypervisor: The monitor sees Data Remaining bumping up and increases max downtime up to 20 seconds, but weird thing is that after a period of time, it started reporting "Data Remaining" and "Data Total" is both 0, but the migration job is still unfinished: "Migration in progress - DataTotal: 85 904728064, DataRemaining: 22201458688, TimeElapsed: 20005, MaxDowntime: 500, DirtyRate: 0" "Migration in progress - DataTotal: 85904728064, DataRemaining: 43801825280, TimeElapsed: 10005, MaxDowntime: 500, DirtyRate: 0" "Migration in progress - DataTotal: 85904728064, DataRemaining: 52382912512, TimeElapsed: 10004, MaxDowntime: 500, DirtyRate: 0" (DataRemaining bumps up, we start increasing max downtime) "Migration in progress - DataTotal: 85904728064, DataRemaining: 4219596800, TimeElapsed: 40004, MaxDowntime: 1500, DirtyRate: 0" (Last poll where we see the job info) After which monitor logs "Migration in progress - DataTotal: 0, DataRemaining: 0, TimeElapsed: 40004, MaxDowntime: 13500, DirtyRate: 0" The domain is always running on the source hypervisor but there is a paused domain on the destination hypervisor which is paused at start up. Trying to understand what might have happened: - Is this a known issue for live migrating high memory activity guests and the way we interact with libvirt? - What is the recommended way to ensure that a started live migration always run to completion if we don't care about downtime? Appreciate any help here Yangchen Ye

1 1

How to disable sysctl calls performed by libvirt?
by Chimmie Firefly 11 Jul '25

11 Jul '25

Hello, I have an issue whenever using `/proc/sys/ipv6/conf` as read-only mountpoint. While the libvirt by itself is running fine, I'm unable to create NAT network interfaces because of the following error: ``` 2025-07-05 19:33:32.821+0000: 100: error : networkSetIPv6Sysctl:1847 : cannot write to '/proc/sys/net/ipv6/conf/virbr0/disable_ipv6' on bridge 'virbr0': Read-only file system 2025-07-05 19:33:32.841+0000: 100: error : virNetDevSetIFFlag:601 : Cannot get interface flags on 'virbr0': No such device 2025-07-05 19:33:32.947+0000: 100: error : virNetlinkDelLink:688 : error destroying network device virbr0: No such device ``` While using iproute2 and bridge utils, I'm able to create and configure new bridge device, along with attaching the VM to the interface. I've used the following commands: ``` sysctl -w net.ipv4.ip_forward=1 brctl addbr br0 ip link set br0 up ip addr add 192.168.100.1/24 dev br0 iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE iptables -A FORWARD -i br0 -o eth0 -j ACCEPT iptables -A FORWARD -i eth0 -o br0 -m state --state RELATED,ESTABLISHED -j ACCEPT ``` Is libvirt allowing to disable sysctl calls in the configuration files? If so, what should I set in the config?

2 1

fsck unable to fix fs issue
by ola . 08 Jul '25

08 Jul '25

I am able to boot VMs by using rbd as the root disk. When I restart and stop the VM everything works fine however, anytime the host goes down say due to a power outage, when next I try to boot the VM, I run into a situation where the root disk gets corrupted and get stuck at "initramfs". I have tried to fix this but to no avail. Here are the errors I get when I try yo use fix the fs issue with fsck manually. done. Begin: Running /scripts/init-premount ... done. Begin: Mounting root file system ... Begin: Running /scripts/local-top ... done. Begin: Running /scripts/local-premount ... [ 7.760625] Btrfs loaded, crc32c=crc32c-intel, zoned=yes, fsverity=yes Scanning for Btrfs filesystems done. Begin: Will now check root file system ... fsck from util-linux 2.37.2 [/usr/sbin/fsck.ext4 (1) -- /dev/vda1] fsck.ext4 -a -C0 /dev/vda1 [ 7.866954] blk_update_request: I/O error, dev vda, sector 0 op 0x1:(WRITE) flags 0x800 phys_seg 0 prio class 0 cloudimg-rootfs: recovering journal [ 8.164279] blk_update_request: I/O error, dev vda, sector 227328 op 0x1:(WRITE) flags 0x800 phys_seg 24 prio class 0 [ 8.168272] Buffer I/O error on dev vda1, logical block 0, lost async page write [ 8.170413] Buffer I/O error on dev vda1, logical block 1, lost async page write [ 8.172545] Buffer I/O error on dev vda1, logical block 2, lost async page write [ 8.174601] Buffer I/O error on dev vda1, logical block 3, lost async page write [ 8.176651] Buffer I/O error on dev vda1, logical block 4, lost async page write [ 8.178694] Buffer I/O error on dev vda1, logical block 5, lost async page write [ 8.180601] Buffer I/O error on dev vda1, logical block 6, lost async page write [ 8.182641] Buffer I/O error on dev vda1, logical block 7, lost async page write [ 8.184710] Buffer I/O error on dev vda1, logical block 8, lost async page write [ 8.186744] Buffer I/O error on dev vda1, logical block 9, lost async page write [ 8.188748] blk_update_request: I/O error, dev vda, sector 229392 op 0x1:(WRITE) flags 0x800 phys_seg 8 prio class 0 [ 8.191433] blk_update_request: I/O error, dev vda, sector 229440 op 0x1:(WRITE) flags 0x800 phys_seg 32 prio class 0 [ 8.194204] blk_update_request: I/O error, dev vda, sector 229480 op 0x1:(WRITE) flags 0x800 phys_seg 16 prio class 0 [ 8.196976] blk_update_request: I/O error, dev vda, sector 229512 op 0x1:(WRITE) flags 0x800 phys_seg 8 prio class 0 [ 8.243612] blk_update_request: I/O error, dev vda, sector 229544 op 0x1:(WRITE) flags 0x800 phys_seg 8 prio class 0 [ 8.246068] blk_update_request: I/O error, dev vda, sector 229640 op 0x1:(WRITE) flags 0x800 phys_seg 32 prio class 0 [ 8.248668] blk_update_request: I/O error, dev vda, sector 229688 op 0x1:(WRITE) flags 0x800 phys_seg 8 prio class 0 [ 8.251174] blk_update_request: I/O error, dev vda, sector 229704 op 0x1:(WRITE) flags 0x800 phys_seg 8 prio class 0 fsck.ext4: Input/output error while recovering journal of cloudimg-rootfs fsck.ext4: unable to set superblock flags on cloudimg-rootfs cloudimg-rootfs: ********** WARNING: Filesystem still has errors ********** fsck exited with status code 12 done. Failure: File system check of the root filesystem failed The root filesystem on /dev/vda1 requires a manual fsck BusyBox v1.30.1 (Ubuntu 1:1.30.1-7ubuntu3.1) built-in shell (ash) Enter 'help' for a list of built-in commands. (initramfs) fsck.ext4 -f -y /dev/vda1 e2fsck 1.46.5 (30-Dec-2021) [ 24.286341] print_req_error: 174 callbacks suppressed [ 24.286358] blk_update_request: I/O error, dev vda, sector 0 op 0x1:(WRITE) flags 0x800 phys_seg 0 prio class 0 cloudimg-rootfs: recovering journal [ 24.552343] blk_update_request: I/O error, dev vda, sector 227328 op 0x1:(WRITE) flags 0x800 phys_seg 24 prio class 0 [ 24.556674] buffer_io_error: 5222 callbacks suppressed [ 24.558925] Buffer I/O error on dev vda1, logical block 0, lost async page write [ 24.562116] Buffer I/O error on dev vda1, logical block 1, lost async page write [ 24.565161] Buffer I/O error on dev vda1, logical block 2, lost async page write [ 24.567872] Buffer I/O error on dev vda1, logical block 3, lost async page write [ 24.570586] Buffer I/O error on dev vda1, logical block 4, lost async page write [ 24.573418] Buffer I/O error on dev vda1, logical block 5, lost async page write [ 24.575940] Buffer I/O error on dev vda1, logical block 6, lost async page write [ 24.578622] Buffer I/O error on dev vda1, logical block 7, lost async page write [ 24.581386] Buffer I/O error on dev vda1, logical block 8, lost async page write [ 24.583873] Buffer I/O error on dev vda1, logical block 9, lost async page write [ 24.586410] blk_update_request: I/O error, dev vda, sector 229392 op 0x1:(WRITE) flags 0x800 phys_seg 8 prio class 0 [ 24.589821] blk_update_request: I/O error, dev vda, sector 229440 op 0x1:(WRITE) flags 0x800 phys_seg 32 prio class 0 [ 24.593380] blk_update_request: I/O error, dev vda, sector 229480 op 0x1:(WRITE) flags 0x800 phys_seg 16 prio class 0 [ 24.596615] blk_update_request: I/O error, dev vda, sector 229512 op 0x1:(WRITE) flags 0x800 phys_seg 8 prio class 0 [ 24.643829] blk_update_request: I/O error, dev vda, sector 229544 op 0x1:(WRITE) flags 0x800 phys_seg 8 prio class 0 [ 24.646924] blk_update_request: I/O error, dev vda, sector 229640 op 0x1:(WRITE) flags 0x800 phys_seg 32 prio class 0 [ 24.650051] blk_update_request: I/O error, dev vda, sector 229688 op 0x1:(WRITE) flags 0x800 phys_seg 8 prio class 0 [ 24.653128] blk_update_request: I/O error, dev vda, sector 229704 op 0x1:(WRITE) flags 0x800 phys_seg 8 prio class 0 fsck.ext4: Input/output error while recovering journal of cloudimg-rootfs fsck.ext4: unable to set superblock flags on cloudimg-rootfs cloudimg-rootfs: ********** WARNING: Filesystem still has errors ********** This is what my rbd disk looks like <disk type='network' device='disk'> <driver name='qemu' type='raw' cache='none' io='native'/> <auth username='dove'> <secret type='ceph' uuid='b608caae-5eb4-45cc-bfd4-0b4ac11c7613'/> </auth> <source protocol='rbd' name='vms/wing-64700f1d-8c469a54-3f50-4d1e-9db2-2b6ea5f3d14a'> <host name='x.168.1.x' port='6789'/> </source> <target dev='vda' bus='virtio'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/> </disk> So, my questions are; - How do I prevent this from happening as i have tried different options like changing the "cache" value for the disk template? - How can this be fixed? Thanks

2 1

RBD Namespace
by Rodrigo Prieto 23 Jun '25

23 Jun '25

Hello, I want to connect to an RBD pool specifying the namespace, but it doesn’t work. If I connect directly to the pool, it works. For example: <source protocol="rbd" name="rbd-pool/vm"> But when I try to specify the namespace like this, I cannot connect: <source protocol="rbd" name="rbd-pool/vm" namespace="vms"> <source protocol="rbd" name="rbd-pool/vms/vm"> Error al iniciar dominio: error interno: process exited while connecting to monitor: 2025-06-20T22:54:55.076193Z qemu-system-x86_64: -blockdev {"driver":"rbd","pool":"rbd-pool","image":"loli/mari","server":[{"host":"ceph-admin","port":"6789"}],"user":"admin","auth-client-required":["cephx","none"],"key-secret":"libvirt-2-storage-auth-secret0","node-name":"libvirt-2-storage","auto-read-only":true,"discard":"unmap"}: error reading header from loli/mari: No such file or directory Using the rbd command from the terminal, I can connect both ways; the error occurs only with libvirt. I’m using the following versions on Debian 12: libvirtd (libvirt) 9.0.0 QEMU emulator version 7.2.17 (Debian 1:7.2+dfsg-7+deb12u13) Copyright (c) 2003-2022 Fabrice Bellard and the QEMU Project developers Thanks.

2 2

Re: Question about managed/unmanaged persistent reservation disks
by Michal Prívozník 17 Jun '25

17 Jun '25

On 6/10/25 19:15, Simon Coter wrote: > Adding users DL to possibly reach out a wider audience. > > Simon > Dropping devel list as this is users list material. >> On Jun 9, 2025, at 7:28 PM, Annie Li <annie.li(a)oracle.com> wrote: >> >> Hello, >> >> I've been looking at source code related to persistent reservation and >> got confused a little bit about managed persistent reservation disks. >> For disk configured with 'managed=yes' as the following, >> >> <reservations managed='yes'> >> <source type='unix' path='/var/lib/libvirt/qemu/domain-7- >> brml10g19-iscsi-rese/pr-helper0.sock' mode='client'/> >> </reservations> >> >> libvirt is responsible for starting a pr-helper program with a >> specific associated socket file. The following source code shows that >> there is only one pr-helper and socket file associated with the >> managed disks for one VM. >> >> const char * >> qemuDomainGetManagedPRAlias(void) >> { >> return "pr-helper0"; >> } >> char * >> qemuDomainGetManagedPRSocketPath(qemuDomainObjPrivate *priv) >> { >> return g_strdup_printf("%s/%s.sock", priv->libDir, >> qemuDomainGetManagedPRAlias()); >> } >> >> So if the VM is booted with multiple disks configured with >> 'managed=yes' for reservation, I suppose these multiple disks share >> the this managed pr-helper and socket file. However, per the qemu >> document, https://www.qemu.org/docs/master/interop/pr-helper.html >> <https://www.qemu.org/docs/master/interop/pr-helper.html> >> "It is invalid to send multiple commands concurrently on the same >> socket. It is however possible to connect multiple sockets to the >> helper and send multiple commands to the helper for one or more file >> descriptors." >> This certainly did not use to be the case. IIRC this was discussed in this very old thread: https://lists.libvirt.org/archives/list/devel@lists.libvirt.org/thread/UUL3… Maybe QEMU has some internal lock that does the right thing and serializes requests? Michal >> Due to this limitation above, only one persistent reservation disk is >> allowed as managed in theory. However, libvirt doesn't throw out any >> error or warning when the VM is booted up with multiple managed >> persistent reservation disks. I am wondering if I've missed something >> here? >> >> For unmanaged persistent reservation disks, libvirt doesn't start the >> pr-helper program for them. It is user's responsibility to start this >> program with customized socket file per disk, but the complexity >> increases with numbers of persistent reservation disks, especially in >> the case of hotplug/hotunplog. Is there any plan to support multiple >> managed persistent reservation disks with separate pr-helper/socket file? >> >> Any suggestions/clarifications are greatly appreciated. >> >> Thanks >> >> Annie >> >

3 7

significant delay live migrating a vm with an sr-iov interface
by Paul B. Henson 10 Jun '25

10 Jun '25

I'm using libvirt under Debian 12 (9.0.0-4+deb12u2 w/qemu 7.2+dfsg-7+deb12u12). I have a vm using sr-iov, and configured it with a failover macvtap interface so I could live migrate it. However, there is a significant delay at the end of the migration resulting in a lot of lost traffic. If I only have the macvtap interface, migration completes immediately at the end of the transfer of memory with no loss of traffic. I enabled debug logging, and found the following. On the source system, it logs that the system is paused for the cutover: 2025-04-30 01:08:12.526+0000: 1696180: debug : qemuMigrationAnyCompleted:1957 : Migration paused before switchover at that point, for almost a minute, the source system just keeps printing the same statistics: 2025-04-30 01:08:12.923+0000: 1696272: info : qemuMonitorJSONIOProcessLine:208 : QEMU_MONITOR_RECV_REPLY: mon=0x7f8fdc0ad2f0 reply={"return": {"expected-downtime": 300, "status": "device", "setup-time": 297, "total-time": 26107, "ram": {"total": 137452265472, "postcopy-requests": 0, "dirty-sync-count": 3, "multifd-bytes": 2821784576, "pages-per-second": 297855, "downtime-bytes": 13208, "page-size": 4096, "remaining": 0, "postcopy-bytes": 0, "mbps": 9786.9158461538464, "transferred": 3117658825, "dirty-sync-missed-zero-copy": 0, "precopy-bytes": 295861041, "duplicate": 32874480, "dirty-pages-rate": 56, "skipped": 0, "normal-bytes": 2804301824, "normal": 684644}}, "id": "libvirt-577"} [...] 2025-04-30 01:09:06.290+0000: 1696272: info : qemuMonitorJSONIOProcessLine:208 : QEMU_MONITOR_RECV_REPLY: mon=0x7f8fdc0ad2f0 reply={"return": {"expected-downtime": 300, "status": "device", "setup-time": 297, "total-time" : 79474, "ram": {"total": 137452265472, "postcopy-requests": 0, "dirty-sync-count": 3, "multifd-bytes": 2821784576, "pages-per-second": 297855, "downtime-bytes": 13208, "page-size": 4096, "remaining": 0, "postcopy-bytes" : 0, "mbps": 9786.9158461538464, "transferred": 3117658825, "dirty-sync-missed-zero-copy": 0, "precopy-bytes": 295861041, "duplicate": 32874480, "dirty-pages-rate": 56, "skipped": 0, "normal-bytes": 2804301824, "normal": 684644}}, "id": "libvirt-629"} until finally it completes: 2025-04-30 01:09:06.327+0000: 1696272: info : qemuMonitorJSONIOProcessLine:203 : QEMU_MONITOR_RECV_EVENT: mon=0x7f8fdc0ad2f0 event={"timestamp": {"seconds": 1745975346, "microseconds": 327382}, "event": "MIGRATION", "dat a": {"status": "completed"}} On the destination side, it says something about negotiating failover for the network link: 2025-04-30 01:08:12.923+0000: 1384503: info : qemuMonitorJSONIOProcessLine:203 : QEMU_MONITOR_RECV_EVENT: mon= 0x7fc7900ab2f0 event={"timestamp": {"seconds": 1745975292, "microseconds": 922783}, "event": "FAILOVER_NEGOTIA TED", "data": {"device-id": "ua-sr-iov-backup"}} Then nothing happens for about a minute until it says it is done: 2025-04-30 01:09:06.328+0000: 1384503: debug : qemuMonitorJSONIOProcessLine:189 : Line [{"timestamp": {"second s": 1745975346, "microseconds": 327991}, "event": "MIGRATION", "data": {"status": "completed"}}] Any thoughts on what is going on here to cause this delay? It's clearly somehow related to the sv-iov component of the migration. Thanks much…

2 1

virt-install iscsi direct - Target not found
by kgore4 une 10 Jun '25

10 Jun '25

When I try to use an iscsi direct pool in a "--disk" clause for virt-install, I get error "iSCSI: Failed to connect to LUN : Failed to log in to target. Status: Target not found(515)". I've seen that sort of error before when the initiator name isn't used. The SAN returns different LUNS depending on the initiator. I've run out of ideas on what to try next. Any advice welcome. I've included what I thought was relevent below. klint. The disk parameter to virt-install is (it's part of a script but the variables are correct when executed) [code] --disk vol=${poolName}/unit:0:0:${vLun1},xpath.set="./source/initiator/iqn/@name='iqn.2024-11.localdomain.agbu.agbuvh1:${vName}'" \ [/code] I added the xpath.set as I noticed that the initiator wasn't in the debug output of the disk definition and it didn't work without it either. The iscsi direct pool is defined and it appears to work - it's active and vol-list shows the correct luns. Using --debug on virt install, I can see the drive is detected early in the process as it's got the size of the drive. [code] [Wed, 19 Feb 2025 16:43:33 virt-install 2174805] DEBUG (cli:3554) Parsed --disk volume as: pool=agbu-ldap1 vol=unit:0:0:3 [Wed, 19 Feb 2025 16:43:33 virt-install 2174805] DEBUG (disk:648) disk.set_vol_object: volxml= <volume type='network'> <name>unit:0:0:3</name> <key>ip-10.1.4.3:3260-iscsi-iqn.1992-09.com.seagate:01.array.00c0fff6c846-lun-3</key> <capacity unit='bytes'>49996103168</capacity> <allocation unit='bytes'>49996103168</allocation> <target> <path>ip-10.1.4.3:3260-iscsi-iqn.1992-09.com.seagate:01.array.00c0fff6c846-lun-3</path> </target> </volume> [Wed, 19 Feb 2025 16:43:33 virt-install 2174805] DEBUG (disk:650) disk.set_vol_object: poolxml= <pool type='iscsi-direct'> <name>agbu-ldap1</name> <uuid>1c4ae810-9bae-433c-a92f-7d3501b6ba80</uuid> <capacity unit='bytes'>49996103168</capacity> <allocation unit='bytes'>49996103168</allocation> <available unit='bytes'>0</available> <source> <host name='10.1.4.3'/> <device path='iqn.1992-09.com.seagate:01.array.00c0fff6c846'/> <initiator> <iqn name='iqn.2024-11.localdomain.agbu.agbuvh1:agbu-ldap'/> </initiator> </source> </pool> [/code] The generated initial_xml for the disk looks like [code] <disk type="network" device="disk"> <driver name="qemu" type="raw"/> <source protocol="iscsi" name="iqn.1992-09.com.seagate:01.array.00c0fff6c846-lun-3"> <host name="10.1.4.3"/> <initiator> <iqn name="iqn.2024-11.localdomain.agbu.agbuvh1:agbu-ldap"/> </initiator> </source> <target dev="vda" bus="virtio"/> </disk> [/code] The generated final_xml looks like [code] <disk type="network" device="disk"> <driver name="qemu" type="raw"/> <source protocol="iscsi" name="iqn.1992-09.com.seagate:01.array.00c0fff6c846-lun-3"> <host name="10.1.4.3"/> <initiator> <iqn name="iqn.2024-11.localdomain.agbu.agbuvh1:agbu-ldap"/> </initiator> </source> <target dev="vda" bus="virtio"/> </disk> [/code] The full error is [code] [Wed, 19 Feb 2025 16:43:35 virt-install 2174805] DEBUG (cli:256) File "/usr/bin/virt-install", line 8, in <module> virtinstall.runcli() File "/usr/share/virt-manager/virtinst/virtinstall.py", line 1233, in runcli sys.exit(main()) File "/usr/share/virt-manager/virtinst/virtinstall.py", line 1226, in main start_install(guest, installer, options) File "/usr/share/virt-manager/virtinst/virtinstall.py", line 974, in start_install fail(e, do_exit=False) File "/usr/share/virt-manager/virtinst/cli.py", line 256, in fail log.debug("".join(traceback.format_stack())) [Wed, 19 Feb 2025 16:43:35 virt-install 2174805] ERROR (cli:257) internal error: process exited while connecting to monitor: 2025-02-19T05:43:35.075695Z qemu-system-x86_64: -blockdev {"driver":"iscsi","portal":"10.1.4.3:3260","target":"iqn.1992-09.com.seagate:01.array.00c0fff6c846-lun-3","lun":0,"transport":"tcp","initiator-name":"iqn.2024-11.localdomain.agbu.agbuvh1:agbu-ldap","node-name":"libvirt-2-storage","auto-read-only":true,"discard":"unmap"}: iSCSI: Failed to connect to LUN : Failed to log in to target. Status: Target not found(515) [Wed, 19 Feb 2025 16:43:35 virt-install 2174805] DEBUG (cli:259) Traceback (most recent call last): File "/usr/share/virt-manager/virtinst/virtinstall.py", line 954, in start_install domain = installer.start_install( ^^^^^^^^^^^^^^^^^^^^^^^^ File "/usr/share/virt-manager/virtinst/install/installer.py", line 695, in start_install domain = self._create_guest( ^^^^^^^^^^^^^^^^^^^ File "/usr/share/virt-manager/virtinst/install/installer.py", line 637, in _create_guest domain = self.conn.createXML(initial_xml or final_xml, 0) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/usr/lib/python3/dist-packages/libvirt.py", line 4481, in createXML raise libvirtError('virDomainCreateXML() failed') libvirt.libvirtError: internal error: process exited while connecting to monitor: 2025-02-19T05:43:35.075695Z qemu-system-x86_64: -blockdev {"driver":"iscsi","portal":"10.1.4.3:3260","target":"iqn.1992-09.com.seagate:01.array.00c0fff6c846-lun-3","lun":0,"transport":"tcp","initiator-name":"iqn.2024-11.localdomain.agbu.agbuvh1:agbu-ldap","node-name":"libvirt-2-storage","auto-read-only":true,"discard":"unmap"}: iSCSI: Failed to connect to LUN : Failed to log in to target. Status: Target not found(515) [/code] Things that could affect the answer * What I'm calling a SAN is a seagate exos-x iscsi unit * virtual host is debian 12 * virsh version 9.0.0 * iscsiadm version 2.1.8

2 1

Guest cannot access host HTTP service in NAT
by icefrog1950＠gmail.com 02 Jun '25

02 Jun '25

Hi, I hit a libvirt networking problem that guest cannot access host HTTP service. I debug this issue and tried some efforts. Thanks for your suggestions! Environment ------------- guest IP: 192.168.122.46 (Linux, default NAT, installed using virt-manager) host1 IP: 192.168.3.16 (Centos 8.5 running libvirt and qemu, default libvirt iptable rules) HTTP service: 192.168.3.16:70 (firewall rules have allowed this port) host2: 192.168.3.65:70 (for test only) guest network xml <interface type="network"> <mac address="52:54:00:f5:a8:9f"/> <source network="default" portid="6e8ce7e7-6517-43fa-b113-aaddb6c1bc08" bridge="virbr0"/> <target dev="vnet2"/> <model type="e1000"/> <alias name="net0"/> <address type="pci" domain="0x0000" bus="0x00" slot="0x03" function="0x0"/> </interface> 1. guest and host1/host2 can ping each other 2. *guest can visit host2 HTTP 3. *guest cannot visit host1 HTTP When I capture traffic in guest, Wireshark shows: 192.168.122.46 -> 192.168.3.16 // SYN ok 192.168.122.46 <- 192.168.3.16 // Destination unreachable (Port unreachable) guest route table: ------------------ Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 192.168.122.1 0.0.0.0 UG 100 0 0 eth0 192.168.122.0 0.0.0.0 255.255.255.0 U 100 0 0 eth0 host1 route table: ------------------ Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 192.168.3.1 0.0.0.0 UG 100 0 0 enp3s0 192.168.3.0 0.0.0.0 255.255.255.0 U 100 0 0 enp3s0 192.168.122.0 0.0.0.0 255.255.255.0 UG 0 0 0 virbr0 I delete the last rule and add a rule to make sure host1 visits guests will go through 192.168.122.1 ------------------ Destination Gateway Genmask Flags Metric Ref Use Iface (other rules omitted) 192.168.122.0 192.168.122.1 255.255.255.0 UG 0 0 0 virbr0 However, traceroute shows this new rule does not work (which should go to 192.168.122.1 first), and guest cannot visit host1 HTTP request. [!] guest visit http://192.168.3.16:70 does not go through 192.168.122.1 traceroute 192.168.122.46 traceroute to 192.168.122.46 (192.168.122.46), 30 hops max, 60 byte packets 1 192.168.122.46 (192.168.122.46) 0.200 ms 0.194 ms 0.194 ms # guest visit http://192.168.3.65:70 goes through 192.168.122.1 traceroute 192.168.3.65 traceroute to 192.168.3.65 (192.168.3.65), 30 hops max, 60 byte packets 1 192.168.122.1 (192.168.122.1) 0.244 ms 0.050 ms 0.120 ms 2 192.168.3.65 (192.168.3.65) 0.823 ms !X 0.802 ms !X 0.789 ms !X In sum, is there a way to force the guest go through 192.168.122.1 when visiting the hosting machine? ------------------- libvirt iptable rules: -P INPUT ACCEPT -P FORWARD ACCEPT -P OUTPUT ACCEPT -N LIBVIRT_INP -N LIBVIRT_OUT -N LIBVIRT_FWO -N LIBVIRT_FWI -N LIBVIRT_FWX -A INPUT -j LIBVIRT_INP -A FORWARD -j LIBVIRT_FWX -A FORWARD -j LIBVIRT_FWI -A FORWARD -j LIBVIRT_FWO -A OUTPUT -j LIBVIRT_OUT -A LIBVIRT_INP -i virbr0 -p udp -m udp --dport 53 -j ACCEPT -A LIBVIRT_INP -i virbr0 -p tcp -m tcp --dport 53 -j ACCEPT -A LIBVIRT_INP -i virbr0 -p udp -m udp --dport 67 -j ACCEPT -A LIBVIRT_INP -i virbr0 -p tcp -m tcp --dport 67 -j ACCEPT -A LIBVIRT_OUT -o virbr0 -p udp -m udp --dport 53 -j ACCEPT -A LIBVIRT_OUT -o virbr0 -p tcp -m tcp --dport 53 -j ACCEPT -A LIBVIRT_OUT -o virbr0 -p udp -m udp --dport 68 -j ACCEPT -A LIBVIRT_OUT -o virbr0 -p tcp -m tcp --dport 68 -j ACCEPT -A LIBVIRT_FWO -s 192.168.122.0/24 -i virbr0 -j ACCEPT -A LIBVIRT_FWO -i virbr0 -j REJECT --reject-with icmp-port-unreachable # delete this rule does not work -A LIBVIRT_FWI -d 192.168.122.0/24 -o virbr0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT -A LIBVIRT_FWI -o virbr0 -j REJECT --reject-with icmp-port-unreachable # delete this rule does not work -A LIBVIRT_FWX -i virbr0 -o virbr0 -j ACCEPT

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Booting from DVD
by Vince Schielack III 20 May '25

20 May '25

I have need to pass the host optical drive through to a guest and have the guest boot from it. I can set the boot order and make sure the ROM BAR is enabled, but the VM won’t boot from the dvd unless I explicitly select it in the boot menu (3rd option). I’d like to do this to avoid a lengthy and unnecessary dd copy to an ISO. That would essentially double my system installation time by reading the DVD twice.

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Windows 11 fails to install under QEMU/libvirt while VirtualBox succeeds — why?
by Paul Larochelle 20 May '25

20 May '25

Hello, I'm writing to better understand a surprising discrepancy I encountered while attempting to install Windows 11 in different virtualization environments. On my Arch Linux system, I tested two setups: 1. **VirtualBox (GUI):** Windows 11 installs successfully out of the box. 2. **QEMU/KVM with libvirt (manually crafted XML):** Windows 11 refuses to install, stating that the system doesn't meet the requirements. The libvirt domain configuration includes: - UEFI boot using OVMF (`OVMF_CODE.4m.fd` and `OVMF_VARS.ms.fd`) - TPM 2.0 emulator (`tpm-crb` with `backend type='emulator' version='2.0'`) - Secure Boot enabled (verified using Microsoft-signed vars) - 8 GiB of RAM, 4 vCPUs - VirtIO disk + virtio-win ISO attached - QXL or VirtIO video model - `<hyperv>` feature set enabled - Valid boot order (CD-ROM first, then disk) Despite this, Windows 11 either refuses installation with the "This PC can't run Windows 11" message or fails to detect a valid bootable device. In contrast, VirtualBox seems to pass all checks without exposing TPM configuration explicitly or enabling Secure Boot manually. --- **My question:** What is VirtualBox doing under the hood that makes Windows 11 accept the environment without issues? - Is it exposing a minimal TPM implicitly? - Is it modifying SMBIOS/ACPI fields in a way that satisfies Windows validation logic? - Are there known tricks or missing XML elements in libvirt domains to replicate this behavior? My goal is not to bypass Microsoft's requirements, but rather to understand the technical differences and replicate a compliant setup in QEMU/libvirt, ideally without resorting to ISO modifications. Any insight or guidance would be highly appreciated. Best regards, Paul [signature_paul.png] Paul Larochelle 819 342-5487 Envoyé avec la messagerie sécurisée [Proton Mail.](https://proton.me/mail/home)

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libvirt home assistant integration
by Bram Diederik 16 May '25

16 May '25

Hello libvirt users. I had fun with chatgpt (and lots of frustration) and created an integration I missed for some time for home assistant: a libvirt integration. view your libvirt systems inside home assistant, control them. (state and snapshot control) and have the display shown as a camera. https://github.com/Bram-diederik/home-assistant-libvirt-integration/ cheers. Bram Diederik

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Cannot restore internal snapshots since libvirt 11.2.0
by anonym 12 May '25

12 May '25

Hi! Since libvirt 11.2.0 attempting to restore internal snapshots fails for me with: error: Failed to revert snapshot foo1 error: operation failed: load of internal snapshot 'foo1' job failed: Device 'libvirt-1-format' is writable but does not support snapshots I reported this issue to GitLab [0] where there is more info and a reproducer, but I also wanted to ask the wider community here if anyone has experienced this and maybe even come up with a workaround? [0] https://gitlab.com/libvirt/libvirt/-/issues/771 Cheers!

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vm stopped booting
by daggs 22 Apr '25

22 Apr '25

Greetings, my windows vm stoop working, I think it is related kernel version, 6.14.1 works but 6.14.2 seems not to looking at the libvirt-qemu log file shows this: 2025-04-22 17:28:52.082+0000: starting up libvirt version: 11.2.0, qemu version: 9.2.3, kernel: 6.14.3-gentoo, hostname: NCC-5001D.lan LC_ALL=C \ PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:/opt/bin:/usr/lib/llvm/19/bin:/etc/eselect/wine/bin:/opt/cuda/bin \ HOME=/var/lib/libvirt/qemu/domain-1-windows \ USER=root \ XDG_DATA_HOME=/var/lib/libvirt/qemu/domain-1-windows/.local/share \ XDG_CACHE_HOME=/var/lib/libvirt/qemu/domain-1-windows/.cache \ XDG_CONFIG_HOME=/var/lib/libvirt/qemu/domain-1-windows/.config \ /usr/bin/qemu-system-x86_64 \ -name guest=windows,debug-threads=on \ -S \ -object '{"qom-type":"secret","id":"masterKey0","format":"raw","file":"/var/lib/libvirt/qemu/domain-1-windows/master-key.aes"}' \ -blockdev '{"driver":"file","filename":"/usr/share/edk2/OvmfX64/OVMF_CODE_4M.secboot.qcow2","node-name":"libvirt-pflash0-storage","auto-read-only":true,"discard":"unmap"}' \ -blockdev '{"node-name":"libvirt-pflash0-format","read-only":true,"driver":"qcow2","file":"libvirt-pflash0-storage","backing":null}' \ -blockdev '{"driver":"file","filename":"/var/lib/libvirt/qemu/nvram/windows_VARS.qcow2","node-name":"libvirt-pflash1-storage","auto-read-only":true,"discard":"unmap"}' \ -blockdev '{"node-name":"libvirt-pflash1-format","read-only":false,"driver":"qcow2","file":"libvirt-pflash1-storage","backing":null}' \ -machine pc-q35-8.1,usb=off,smm=on,dump-guest-core=off,pflash0=libvirt-pflash0-format,pflash1=libvirt-pflash1-format,hpet=off,acpi=on \ -accel kvm \ -cpu host,migratable=on,topoext=on,hv-time=on,hv-relaxed=on,hv-vapic=on,hv-spinlocks=0x1fff,hv-vendor-id=wateverr,kvm=off,host-cache-info=on,l3-cache=off \ -global driver=cfi.pflash01,property=secure,value=on \ -m size=31457280k \ -overcommit mem-lock=off \ -smp 16,sockets=1,dies=1,clusters=1,cores=8,threads=2 \ -object '{"qom-type":"memory-backend-memfd","id":"ram-node0","share":true,"size":32212254720}' \ -numa node,nodeid=0,cpus=0-15,memdev=ram-node0 \ -uuid e8fc4f01-5b87-4e2d-a30f-fb72318688f7 \ -display none \ -no-user-config \ -nodefaults \ -chardev socket,id=charmonitor,fd=27,server=on,wait=off \ -mon chardev=charmonitor,id=monitor,mode=control \ -rtc base=localtime,driftfix=slew \ -global kvm-pit.lost_tick_policy=delay \ -no-shutdown \ -global ICH9-LPC.disable_s3=1 \ -global ICH9-LPC.disable_s4=1 \ -boot strict=on \ -device '{"driver":"pcie-root-port","port":16,"chassis":1,"id":"pci.1","bus":"pcie.0","multifunction":true,"addr":"0x2"}' \ -device '{"driver":"pcie-root-port","port":17,"chassis":2,"id":"pci.2","bus":"pcie.0","addr":"0x2.0x1"}' \ -device '{"driver":"pcie-root-port","port":18,"chassis":3,"id":"pci.3","bus":"pcie.0","addr":"0x2.0x2"}' \ -device '{"driver":"pcie-root-port","port":19,"chassis":4,"id":"pci.4","bus":"pcie.0","addr":"0x2.0x3"}' \ -device '{"driver":"pcie-root-port","port":20,"chassis":5,"id":"pci.5","bus":"pcie.0","addr":"0x2.0x4"}' \ -device '{"driver":"pcie-root-port","port":21,"chassis":6,"id":"pci.6","bus":"pcie.0","addr":"0x2.0x5"}' \ -device '{"driver":"pcie-root-port","port":22,"chassis":7,"id":"pci.7","bus":"pcie.0","addr":"0x2.0x6"}' \ -device '{"driver":"pcie-root-port","port":23,"chassis":8,"id":"pci.8","bus":"pcie.0","addr":"0x2.0x7"}' \ -device '{"driver":"pcie-root-port","port":24,"chassis":9,"id":"pci.9","bus":"pcie.0","multifunction":true,"addr":"0x3"}' \ -device '{"driver":"pcie-root-port","port":25,"chassis":10,"id":"pci.10","bus":"pcie.0","addr":"0x3.0x1"}' \ -device '{"driver":"pcie-root-port","port":26,"chassis":11,"id":"pci.11","bus":"pcie.0","addr":"0x3.0x2"}' \ -device '{"driver":"pcie-root-port","port":27,"chassis":12,"id":"pci.12","bus":"pcie.0","addr":"0x3.0x3"}' \ -device '{"driver":"pcie-root-port","port":28,"chassis":13,"id":"pci.13","bus":"pcie.0","addr":"0x3.0x4"}' \ -device '{"driver":"pcie-root-port","port":29,"chassis":14,"id":"pci.14","bus":"pcie.0","addr":"0x3.0x5"}' \ -device '{"driver":"qemu-xhci","p2":15,"p3":15,"id":"usb","bus":"pci.2","addr":"0x0"}' \ -device '{"driver":"virtio-scsi-pci","id":"scsi0","bus":"pcie.0","addr":"0xc"}' \ -blockdev '{"driver":"file","filename":"/usr/share/drivers/windows/virtio-win.iso","node-name":"libvirt-1-storage","read-only":true}' \ -device '{"driver":"ide-cd","bus":"ide.1","drive":"libvirt-1-storage","id":"sata0-0-1"}' \ -chardev socket,id=chr-vu-fs0,path=/var/lib/libvirt/qemu/domain-1-windows/fs0-fs.sock \ -device '{"driver":"vhost-user-fs-pci","id":"fs0","chardev":"chr-vu-fs0","queue-size":1024,"tag":"home@linux","bus":"pci.6","addr":"0x0"}' \ -netdev '{"type":"tap","fd":"29","vhost":true,"vhostfd":"31","id":"hostnet0"}' \ -device '{"driver":"virtio-net-pci","netdev":"hostnet0","id":"net0","mac":"52:54:00:43:79:55","bus":"pci.1","addr":"0x0"}' \ -chardev pty,id=charserial0 \ -device '{"driver":"isa-serial","chardev":"charserial0","id":"serial0","index":0}' \ -chardev socket,id=chrtpm,path=/run/libvirt/qemu/swtpm/1-windows-swtpm.sock \ -tpmdev emulator,id=tpm-tpm0,chardev=chrtpm \ -device '{"driver":"tpm-tis","tpmdev":"tpm-tpm0","id":"tpm0"}' \ -object '{"qom-type":"input-linux","id":"input0","evdev":"/var/lib/libvirt/helpers_state/windows/mouse-event"}' \ -object '{"qom-type":"input-linux","id":"input1","evdev":"/var/lib/libvirt/helpers_state/windows/keyboard-event","repeat":true,"grab_all":true,"grab-toggle":"ctrl-ctrl"}' \ -audiodev '{"id":"audio1","driver":"none"}' \ -global ICH9-LPC.noreboot=off \ -watchdog-action reset \ -device '{"driver":"vfio-pci","host":"0000:06:00.0","id":"hostdev0","bus":"pci.5","multifunction":true,"addr":"0x0","romfile":"/var/lib/libvirt/roms/gpu-10de:1c82-uefi.rom"}' \ -device '{"driver":"vfio-pci","host":"0000:06:00.1","id":"hostdev1","bus":"pci.5","addr":"0x0.0x1"}' \ -device '{"driver":"vfio-pci","host":"0000:04:00.1","id":"hostdev2","bus":"pci.7","addr":"0x0"}' \ -device '{"driver":"vfio-pci","host":"0000:08:00.4","id":"hostdev3","bus":"pci.4","addr":"0x0"}' \ -device '{"driver":"vfio-pci","host":"0000:03:00.0","id":"hostdev4","bus":"pci.9","addr":"0x0"}' \ -device '{"driver":"usb-host","hostdevice":"/dev/bus/usb/003/002","id":"hostdev5","bus":"usb.0","port":"1"}' \ -device '{"driver":"usb-host","id":"hostdev6","bus":"usb.0","port":"2"}' \ -device '{"driver":"usb-host","hostdevice":"/dev/bus/usb/001/002","id":"hostdev7","bus":"usb.0","port":"3"}' \ -device '{"driver":"virtio-balloon-pci","id":"balloon0","bus":"pci.3","addr":"0x0"}' \ -sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny \ -msg timestamp=on 2025-04-22 17:28:52.084+0000: 5390: debug : virProcessSetMaxMemLock:923 : Locked memory for process 5390 limited to 33285996544 bytes 2025-04-22 17:28:52.084+0000: 5390: debug : virExec:881 : Run hook 0x7fb3b82902a0 0x7fb3bb4435d0 2025-04-22 17:28:52.084+0000: 5390: debug : qemuProcessHook:3136 : Obtaining domain lock 2025-04-22 17:28:52.084+0000: 5390: debug : virDomainLockProcessStart:175 : plugin=0x7fb37016de00 dom=0x7fb3704b9bd0 paused=1 fd=0x7fb3bb4432f0 2025-04-22 17:28:52.084+0000: 5390: debug : virDomainLockManagerNew:130 : plugin=0x7fb37016de00 dom=0x7fb3704b9bd0 withResources=1 2025-04-22 17:28:52.084+0000: 5390: debug : virLockManagerPluginGetDriver:275 : plugin=0x7fb37016de00 2025-04-22 17:28:52.084+0000: 5390: debug : virLockManagerNew:298 : driver=0x7fb3c09e5440 type=0 nparams=5 params=0x7fb3bb4431d0 flags=0x1 2025-04-22 17:28:52.084+0000: 5390: debug : virLockManagerLogParams:96 : key=uuid type=uuid value=e8fc4f01-5b87-4e2d-a30f-fb72318688f7 2025-04-22 17:28:52.084+0000: 5390: debug : virLockManagerLogParams:89 : key=name type=string value=windows 2025-04-22 17:28:52.084+0000: 5390: debug : virLockManagerLogParams:77 : key=id type=uint value=1 2025-04-22 17:28:52.084+0000: 5390: debug : virLockManagerLogParams:77 : key=pid type=uint value=5390 2025-04-22 17:28:52.084+0000: 5390: debug : virLockManagerLogParams:92 : key=uri type=cstring value=qemu:///system 2025-04-22 17:28:52.084+0000: 5390: debug : virDomainLockManagerNew:143 : Adding leases 2025-04-22 17:28:52.084+0000: 5390: debug : virDomainLockManagerNew:148 : Adding disks 2025-04-22 17:28:52.084+0000: 5390: debug : virDomainLockManagerAddImage:87 : Add disk /usr/share/drivers/windows/virtio-win.iso 2025-04-22 17:28:52.084+0000: 5390: debug : virLockManagerAddResource:324 : lock=0x7fb3b0044350 type=0 name=/usr/share/drivers/windows/virtio-win.iso nparams=0 params=(nil) flags=0x1 2025-04-22 17:28:52.084+0000: 5390: debug : virLockManagerAcquire:342 : lock=0x7fb3b0044350 state='<null>' flags=0x3 action=0 fd=0x7fb3bb4432f0 2025-04-22 17:28:52.084+0000: 5390: debug : virLockManagerFree:380 : lock=0x7fb3b0044350 2025-04-22 17:28:52.084+0000: 5390: info : virObjectUnref:378 : OBJECT_UNREF: obj=0x7fb370114eb0 2025-04-22 17:28:52.084+0000: 5390: debug : qemuProcessHook:3181 : Hook complete ret=0 2025-04-22 17:28:52.084+0000: 5390: debug : virExec:883 : Done hook 0 2025-04-22 17:28:52.084+0000: 5390: debug : virExecCommon:456 : Setting child uid:gid to 77:77 with caps 0 2025-04-22 17:28:52.084+0000: 5390: debug : virCommandHandshakeChild:402 : Notifying parent for handshake start on 33 2025-04-22 17:28:52.084+0000: 5390: debug : virCommandHandshakeChild:410 : Waiting on parent for handshake complete on 34 2025-04-22 17:28:52.100+0000: 5390: error : virCommandHandshakeChild:418 : libvirtd quit during handshake: Input/output error libvirt: error : libvirtd quit during handshake: Input/output error 2025-04-22 17:28:52.100+0000: shutting down, reason=failed any hints on what can cause the handshake error?

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