libvirtd 安装后未启用并在 2 分钟后关闭

Question

I have a brand new Fedora Server 36 minimal install and all it will run is KVM.

Did the install with dnf group install "Headless Virtualization" and restarted the server.

systemctl status libvirtd showed it was not running; ie

[root@dell-fedora-kvm ~]# systemctl status libvirtd
○ libvirtd.service - Virtualization daemon
     Loaded: loaded (/usr/lib/systemd/system/libvirtd.service; enabled; vendor preset: disabled)
     Active: inactive (dead)
TriggeredBy: ○ libvirtd-tcp.socket
             ○ libvirtd-admin.socket
             ○ libvirtd-ro.socket
             ○ libvirtd-tls.socket
             ○ libvirtd.socket
       Docs: man:libvirtd(8)
             https://libvirt.org

so I started and enabled it with systemctl start libvirtd and systemctl enable libvirtd

restarted but it still doesn't start automatically. When I start it manually systemctl start libvirtd , this is what I get with status. Not sure this tells us where the issue could be.

root@dell-fedora-kvm ~]# systemctl status libvirtd
● libvirtd.service - Virtualization daemon
     Loaded: loaded (/usr/lib/systemd/system/libvirtd.service; enabled; vendor preset: disabled)
     Active: active (running) since Sun 2022-07-03 16:32:23 AEST; 52s ago
TriggeredBy: ○ libvirtd-tcp.socket
             ● libvirtd-admin.socket
             ● libvirtd-ro.socket
             ○ libvirtd-tls.socket
             ● libvirtd.socket
       Docs: man:libvirtd(8)
             https://libvirt.org
   Main PID: 857 (libvirtd)
      Tasks: 21 (limit: 32768)
     Memory: 44.8M
        CPU: 480ms
     CGroup: /system.slice/libvirtd.service
             ├─ 857 /usr/sbin/libvirtd --timeout 120
             ├─ 957 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default.conf --leasefile-ro --dhcp-script=/usr/libexec/libvirt_leaseshelper
             └─ 958 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default.conf --leasefile-ro --dhcp-script=/usr/libexec/libvirt_leaseshelper

Jul 03 16:32:23 dell-fedora-kvm systemd[1]: Started libvirtd.service - Virtualization daemon.
Jul 03 16:32:24 dell-fedora-kvm dnsmasq[957]: started, version 2.86 cachesize 150
Jul 03 16:32:24 dell-fedora-kvm dnsmasq[957]: compile time options: IPv6 GNU-getopt DBus no-UBus no-i18n IDN2 DHCP DHCPv6 no-Lua TFTP conntrack ipset auth cryptoh>
Jul 03 16:32:24 dell-fedora-kvm dnsmasq-dhcp[957]: DHCP, IP range 192.168.122.2 -- 192.168.122.254, lease time 1h
Jul 03 16:32:24 dell-fedora-kvm dnsmasq-dhcp[957]: DHCP, sockets bound exclusively to interface virbr0
Jul 03 16:32:24 dell-fedora-kvm dnsmasq[957]: reading /etc/resolv.conf
Jul 03 16:32:24 dell-fedora-kvm dnsmasq[957]: using nameserver 127.0.0.53#53
Jul 03 16:32:24 dell-fedora-kvm dnsmasq[957]: read /etc/hosts - 2 addresses
Jul 03 16:32:24 dell-fedora-kvm dnsmasq[957]: read /var/lib/libvirt/dnsmasq/default.addnhosts - 0 addresses
Jul 03 16:32:24 dell-fedora-kvm dnsmasq-dhcp[957]: read /var/lib/libvirt/dnsmasq/default.hostsfile

However the service shuts down after about 2 mins...

[root@dell-fedora-kvm ~]# systemctl status libvirtd
○ libvirtd.service - Virtualization daemon
     Loaded: loaded (/usr/lib/systemd/system/libvirtd.service; enabled; vendor preset: disabled)
     Active: inactive (dead) since Sun 2022-07-03 16:37:25 AEST; 6s ago
TriggeredBy: ○ libvirtd-tcp.socket
             ● libvirtd-admin.socket
             ● libvirtd-ro.socket
             ○ libvirtd-tls.socket
             ● libvirtd.socket
       Docs: man:libvirtd(8)
             https://libvirt.org
    Process: 994 ExecStart=/usr/sbin/libvirtd $LIBVIRTD_ARGS (code=exited, status=0/SUCCESS)
   Main PID: 994 (code=exited, status=0/SUCCESS)
      Tasks: 2 (limit: 32768)
     Memory: 31.7M
        CPU: 330ms
     CGroup: /system.slice/libvirtd.service
             ├─ 957 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default.conf --leasefile-ro --dhcp-script=/usr/libexec/libvirt_leaseshelper
             └─ 958 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default.conf --leasefile-ro --dhcp-script=/usr/libexec/libvirt_leaseshelper

Jul 03 16:35:25 dell-fedora-kvm systemd[1]: Starting libvirtd.service - Virtualization daemon...
Jul 03 16:35:25 dell-fedora-kvm systemd[1]: Started libvirtd.service - Virtualization daemon.
Jul 03 16:35:25 dell-fedora-kvm dnsmasq[957]: read /etc/hosts - 2 addresses
Jul 03 16:35:25 dell-fedora-kvm dnsmasq[957]: read /var/lib/libvirt/dnsmasq/default.addnhosts - 0 addresses
Jul 03 16:35:25 dell-fedora-kvm dnsmasq-dhcp[957]: read /var/lib/libvirt/dnsmasq/default.hostsfile
Jul 03 16:37:25 dell-fedora-kvm systemd[1]: libvirtd.service: Deactivated successfully.
Jul 03 16:37:25 dell-fedora-kvm systemd[1]: libvirtd.service: Unit process 957 (dnsmasq) remains running after unit stopped.
Jul 03 16:37:25 dell-fedora-kvm systemd[1]: libvirtd.service: Unit process 958 (dnsmasq) remains running after unit stopped.

I have not made any changes to libvirtd.service . Any idea what's going on?

Answer 1

In Fedora 35, the libvirt default installation was switched to use virtqemud

https://fedoraproject.org/wiki/Changes/LibvirtModularDaemons

Furthermore, regardless of whether an install is configured to use libvirtd or virtqemud , there is no need for the services to be running at install time. They all make use of systemd socket activation, so they will start automatically whenever some application tries to use libvirt. They will stay running as long as application is connected, and shutdown 2 minutes after the last app disconnects (unless VMs are actively running).