Comment 1 for bug 1865523

To make this work I had to use pacemaker from upstream (Vanilla) version: 1.1.19-0

$ dpkg -l | grep 1.1.19 | awk '{print $2" "$3}'
libcib4:amd64 1.1.19-0ubuntu1
libcrmcluster4:amd64 1.1.19-0ubuntu1
libcrmcommon3:amd64 1.1.19-0ubuntu1
libcrmservice3:amd64 1.1.19-0ubuntu1
liblrmd1:amd64 1.1.19-0ubuntu1
libpe-rules2:amd64 1.1.19-0ubuntu1
libpe-status10:amd64 1.1.19-0ubuntu1
libpengine10:amd64 1.1.19-0ubuntu1
libstonithd2:amd64 1.1.19-0ubuntu1
libtransitioner2:amd64 1.1.19-0ubuntu1
pacemaker 1.1.19-0ubuntu1
pacemaker-cli-utils 1.1.19-0ubuntu1
pacemaker-common 1.1.19-0ubuntu1
pacemaker-doc 1.1.19-0ubuntu1
pacemaker-resource-agents 1.1.19-0ubuntu1

AND fence-agents from Ubuntu Eoan:

fence-agents 4.2.1-1

Only after that "combination" I was able to make fence_scsi agent to work:

(k)rafaeldtinoco@clubionic01:~$ crm conf show
node 1: clubionic01.private
node 2: clubionic02.private
node 3: clubionic03.private
primitive fence_clubionic stonith:fence_scsi \
        params pcmk_host_list="clubionic01.private clubionic02.private clubionic03.private" devices="/dev/sda" \
        meta provides=unfencing
property cib-bootstrap-options: \
        have-watchdog=false \
        dc-version=1.1.19-1.1.19 \
        cluster-infrastructure=corosync \
        cluster-name=clubionic \
        stonith-enabled=true \
        stonith-action=off \
        no-quorum-policy=stop

with proper reservations being made:

(k)rafaeldtinoco@clubionic03:~$ sudo sg_persist --in --read-keys --device=/dev/sda
  LIO-ORG cluster.bionic. 4.0
  Peripheral device type: disk
  PR generation=0x4, 3 registered reservation keys follow:
    0x3abe0002
    0x3abe0000
    0x3abe0001