https://unix.stackexchange.com/questions/450308/how-to-allow-specific-proxmox-lxc-containers-to-mount-nfs-shares-on-the-network

Yes, it's possible. Simply create a new profile (based on lxc-container-default-cgns) and use it for the specific containers. So first run

cp /etc/apparmor.d/lxc/lxc-default-cgns /etc/apparmor.d/lxc/lxc-default-with-nfs

Then edit the new file /etc/apparmor.d/lxc/lxc-default-with-nfs:

replace profile lxc-container-default-cgns by profile lxc-container-default-with-nfs put the NFS configuration (see below) just before the closing bracket (}) NFS configuration

Either write

mount fstype=nfs*,
mount fstype=rpc_pipefs,

or (being more explicit)

mount fstype=nfs,
mount fstype=nfs4,
mount fstype=nfsd,
mount fstype=rpc_pipefs,

and finally run service apparmor reload.

Use the new profile

Edit /etc/pve/lxc/${container_id}.conf and append this line:
lxc.apparmor.profile: lxc-container-default-with-nfs

Then stop the container and start it again, e.g. like this:

pct stop ${container_id} && pct start ${container_id}

Now mounting NFS shares should work.

https://www.reddit.com/r/Proxmox/comments/avk2gx/help_cluster_not_ready_no_quorum_500/

systemctl stop pve-cluster
systemctl stop corosync
pmxcfs -l
rm /etc/pve/corosync.conf
rm /etc/corosync/*
killall pmxcfs
systemctl start pve-cluster

vzdump 130 --mode stop
scp tar new_node
pct restore 1234 var/lib/vz/dump/vzdump-lxc-1234-2016_03_02-02_31_03.tar.gz -ignore-unpack-errors 1 -unprivileged

lxc.apparmor.profile = unconfined
do /usr/lib/lxc/ID.conf
pak lxc-stop -n ID
lxc-start -n ID
by default je to lxc brutalne unprivileged

Waiting for UNMS to start
CONTAINER ID        IMAGE                     COMMAND                  CREATED             STATUS              PORTS                                            NAMES
51d5a2823aef        ubnt/unms:1.1.2           "/usr/bin/dumb-init …"   9 seconds ago       Up 6 seconds                                                         unms
320bb0c8b23e        ubnt/unms-crm:3.1.2       "make server_with_mi…"   10 seconds ago      Up 8 seconds        80-81/tcp, 443/tcp, 9000/tcp, 2055/udp           ucrm
c8ced9596c84        ubnt/unms-netflow:1.1.2   "/usr/bin/dumb-init …"   11 seconds ago      Up 7 seconds        0.0.0.0:2055->2055/udp                           unms-netflow
27b9c3344742        redis:5.0.5-alpine        "docker-entrypoint.s…"   15 seconds ago      Up 11 seconds                                                        unms-redis
1f1fd4ad8b11        ubnt/unms-nginx:1.1.2     "/entrypoint.sh ngin…"   15 seconds ago      Up 10 seconds       0.0.0.0:80-81->80-81/tcp, 0.0.0.0:443->443/tcp   unms-nginx
dcbc960d019f        postgres:9.6.12-alpine    "docker-entrypoint.s…"   15 seconds ago      Up 12 seconds                                                        unms-postgres
1ac50d102245        rabbitmq:3.7.14-alpine    "docker-entrypoint.s…"   15 seconds ago      Up 13 seconds                                                        unms-rabbitmq
a34be8e22abe        ubnt/unms-fluentd:1.1.2   "/entrypoint.sh /bin…"   17 seconds ago      Up 15 seconds       5140/tcp, 127.0.0.1:24224->24224/tcp             unms-fluentd
UNMS is running

dle https://www.thegeekdiary.com/how-to-change-pacemaker-cluster-heartbeat-timeout-in-centos-rhel-7/ jsem dal do /etc/pve/corosync.conf „token: 9500“ a to by mohlo prodlouzit quorum timeout na 10sekund

With old systemd there is no console and network in centos and other systems in proxmox 7. Solutin is to install newer version of systemd.

Workaround proposed on https://forum.proxmox.com/threads/pve-7-wont-start-centos-7-container.97834/post-425419:

1. gain access to the CT with pct enter <CTID>
2. enable the network with ifup eth0
3. download this yum repository: https://copr.fedorainfracloud.org/coprs/jsynacek/systemd-backports-for-centos-7/
4. curl -o /etc/yum.repos.d/jsynacek-systemd-backports-for-centos-7-epel-7.repo https://copr.fedorainfracloud.org/coprs/jsynacek/systemd-backports-for-centos-7/repo/epel-7/jsynacek-systemd-backports-for-centos-7-epel-7.repo
5. issue yum update
6. exit from the CT
7. stop the CT with pct stop <CTID>
8. start the CT normally

add to file /etc/pve/corosync.conf

quorum {
    provider: corosync_votequorum
    two_node: 1
    wait_for_all: 0
}