Unbound package 1.5.1_2 issue
I am running four servers with 2.1.5-RELEASE (amd64) on Intel(R) Atom(TM) CPU C2758 @ 2.40GHz. Two servers are at each end of a VPN connection using carp.
Unbound is in use for a long time on all servers without issues. When upgrading the unbound package to 1.5.1_2 today, the pair of servers on one side keeps in good shape while the pair of servers on the other side fail in a way that I had to revert to the DNS forwarder.
All my efforts to determine reasons for the difference in behavior did fail. I tried to align packages used, disabled shell commands run and the like. The pair of servers at one end does fail. Resources are not limited in general, e. g., 19 % of the 16GB of RAM are in use. The failing side has more VLAN interfaces and has 1:1 NAT in use, however, that should not be critical, I think.
The system log then contains the following message:
php: config.inc: The command '/usr/pbi/unbound-amd64/sbin/unbound-control start' returned exit code '1', the output was ' unbound[44948:0] warning: too many file descriptors requested. The builtinmini-event cannot handle more than 1024. Config for less fds or compile with libevent  unbound[44948:0] fatal error: too much tcp. not enough fds.'
To me, this looks like the following issue:
Is there a way to re-enable unbound on the affected systems?
PBI was built without LIBEVENT because option name has changed. I'm building fresh PBIs and will let you know as soon as they are ready
Done, please update to 1.5.1_2_1, make sure PBI is reinstalled since its version didn't change.
Thank you very much for your prompt response, Renato! Deleting unbound 1.5.1_2 and installing 1.5.1_2_1 makes unbound work again on all four servers. Regards, Michael