Gitlab upgrade

Hello,
I was runinng 10.6.3 and I tried to install 10.8.6 via

yum install gitlab-ce10.8.6

I’m running centos7.
The upgrade was stuck for 15m, so I killed the process with CRTL+C.
Then logged in on the server and I see the version is updated. The only thing is that I see the alert manager is not running :

[root@cmd-scm ~]# gitlab-ctl status
warning: alertmanager: unable to open supervise/ok: file does not exist
run: gitaly: (pid 7441) 193s; run: log: (pid 18917) 11992276s
run: gitlab-monitor: (pid 7455) 193s; run: log: (pid 19146) 11992264s
run: gitlab-workhorse: (pid 7471) 192s; run: log: (pid 18588) 11992314s
run: logrotate: (pid 7492) 192s; run: log: (pid 18835) 11992282s
run: nginx: (pid 7509) 191s; run: log: (pid 18664) 11992308s
run: node-exporter: (pid 7523) 191s; run: log: (pid 19080) 11992270s
run: postgres-exporter: (pid 7607) 190s; run: log: (pid 19349) 11992246s
run: postgresql: (pid 7620) 190s; run: log: (pid 18135) 11992388s
run: prometheus: (pid 7632) 189s; run: log: (pid 19271) 11992252s
run: redis: (pid 7654) 189s; run: log: (pid 18016) 11992394s
run: redis-exporter: (pid 7672) 189s; run: log: (pid 19205) 11992258s
run: sidekiq: (pid 7699) 188s; run: log: (pid 18523) 11992320s
run: unicorn: (pid 7711) 186s; run: log: (pid 18451) 11992326s

It says the supervisor does not exists.

[root@cmd-scm ~]# readlink -f /opt/gitlab/service/alertmanager
/opt/gitlab/sv/alertmanager
[root@cmd-scm ~]# /opt/gitlab/embedded/bin/sv once alertmanager
warning: alertmanager: unable to open supervise/ok: file does not exist

Not sure what that is and how to solve it.
When doing a reconfigure it will stop at run for the alertmanager.
Can you please help? We would like to install gitlab 11.1.1.

Thanks,
Nicola