Unbound won't start on system boot

[Jeffrey Walton]

On Thu, Jun 12, 2025 at 11:03 AM Robert Moskowitz via ubuntu-users
<ubuntu-users at lists.ubuntu.com> wrote:
>
> I am still fighting with local resolution.  That is a separate
> question.  But
>
> On reboot, unbound fails to start, but restarts just fine later. One
> google dig found:
>
> "The problem seems to relate to "nss-lookup", and I suspect that the
> network interface is not available fast enough"
>
> So put in your /etc/crontab
>
> @reboot     /bin/systemctl restart unbound
>
> !!!  that seems rather heavy-handed!
>
> So here is what status is showing after booting:
>
> × unbound.service - Unbound DNS server
>       Loaded: loaded (/usr/lib/systemd/system/unbound.service; enabled;
> preset: enabled)
>       Active: failed (Result: exit-code) since Thu 2025-06-12 10:47:17
> EDT; 1min 31s ago
>         Docs: man:unbound(8)
>      Process: 1056 ExecStartPre=/usr/libexec/unbound-helper chroot_setup
> (code=exited, status=0/SUCCESS)
>      Process: 1058 ExecStartPre=/usr/libexec/unbound-helper
> root_trust_anchor_update (code=exited, status=0/SUCCESS)
>      Process: 1061 ExecStart=/usr/sbin/unbound -d -p $DAEMON_OPTS
> (code=exited, status=1/FAILURE)
>      Process: 1064 ExecStopPost=/usr/libexec/unbound-helper
> chroot_teardown (code=exited, status=0/SUCCESS)
>     Main PID: 1061 (code=exited, status=1/FAILURE)
>          CPU: 43ms
>
> ================= later on restart:
>
> Jun 12 10:47:17 onlo systemd[1]: unbound.service: Scheduled restart job,
> restart counter is at 5.
> Jun 12 10:47:17 onlo systemd[1]: unbound.service: Start request repeated
> too quickly.
> Jun 12 10:47:17 onlo systemd[1]: unbound.service: Failed with result
> 'exit-code'.
> Jun 12 10:47:17 onlo systemd[1]: Failed to start unbound.service -
> Unbound DNS server.
> ● unbound.service - Unbound DNS server
>       Loaded: loaded (/usr/lib/systemd/system/unbound.service; enabled;
> preset: enabled)
>       Active: active (running) since Thu 2025-06-12 10:49:20 EDT; 27s ago
>         Docs: man:unbound(8)
>      Process: 1262 ExecStartPre=/usr/libexec/unbound-helper chroot_setup
> (code=exited, status=0/SUCCESS)
>      Process: 1265 ExecStartPre=/usr/libexec/unbound-helper
> root_trust_anchor_update (code=exited, status=0/SUCCESS)
>     Main PID: 1267 (unbound)
>        Tasks: 1 (limit: 8175)
>       Memory: 8.3M (peak: 8.3M)
>          CPU: 88ms
>       CGroup: /system.slice/unbound.service
>               └─1267 /usr/sbin/unbound -d -p
>
> Jun 12 10:49:20 onlo systemd[1]: Starting unbound.service - Unbound DNS
> server...
> Jun 12 10:49:20 onlo (unbound)[1267]: unbound.service: Referenced but
> unset environment variable evaluates to an empty string: DAEMON_OPTS
> Jun 12 10:49:20 onlo unbound[1267]: [1267:0] notice: init module 0:
> subnetcache
> Jun 12 10:49:20 onlo unbound[1267]: [1267:0] warning: subnetcache:
> prefetch is set but not working for data originating from the subnet
> module cache.
> Jun 12 10:49:20 onlo unbound[1267]: [1267:0] notice: init module 1:
> validator
> Jun 12 10:49:20 onlo unbound[1267]: [1267:0] notice: init module 2: iterator
> Jun 12 10:49:20 onlo unbound[1267]: [1267:0] info: start of service
> (unbound 1.19.2).
> Jun 12 10:49:20 onlo systemd[1]: Started unbound.service - Unbound DNS
> server.

<https://www.google.com/search?q=systemd+backoff+retry+start+service>

Jeff