Delete a cluster

list all containers

pct list

stop services

systemctl stop pvestatd
systemctl stop pvedaemon
systemctl stop corosync
systemctl stop pve-cluster

edit through sqlite, check, delete, verify

sqlite3 /var/lib/pve-cluster/config.db 
sqlite> select * from tree where name = 'corosync.conf'; 
sqlite> delete from tree where name = 'corosync.conf'; 
sqlite> select * from tree where name = 'corosync.conf'; 
sqlite> .quit

Remove directories

pmxcfs -l 
rm /etc/pve/corosync.conf 
rm -r /etc/corosync/* 
rm -r /var/lib/corosync/* 
rm -f /var/lib/pve-cluster/.pmxcfs.lockfile

start services

systemctl start pvestatd.service systemctl start pvedaemon.service 
systemctl start pve-cluster.service systemctl start corosync
systemctl start pve-cluster

Create cluster and add computer to a cluster

Create cluster (change clustername, can't be change after)

pvecm create CLUSTERNAME

show cluster's status

pvecm status

add slave computer to the cluster

note that we need to have the param PasswordAuthentication to yes on the host

pvecm add HOST_IP -use_ssh

open ports on slave

sudo ufw allow from HOST_IP to any