Unbound won't start on system boot

[Robert Moskowitz]

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.