My fstab on PVE host:
root@pve:~# cat /etc/fstab
# <file system> <mount point> <type> <options> <dump> <pass>
/dev/pve/root / ext4 errors=remount-ro 0 1
UUID=9DAB-BECF /boot/efi vfat defaults 0 1
/dev/pve/swap none swap sw 0 0
proc /proc proc defaults 0 0
# For smb service from windows server
# Directory where I put ar code image for GeneDatabank application
//192.168.0.100/share\040full/qrCodeImage /mnt/lxc_shares/qrCodeImage cifs _netdev,x-systemd.automount,noatime,uid=100000,gid=100987,dir_mode=0770,file_mode=0770,credentials=/root/.smb 0 0
# Directory where I put the backup (database and others files) for GeneDataBank application
//192.168.0.100/Backup_GeneDataBank /mnt/lxc_shares/Backup_GeneDataBank cifs _netdev,x-systemd.automount,noatime,uid=100000,gid=100987,dir_mode=0770,file_mode=0770,credentials=/root/.smb 0 0
and my lxc conf
root@pve:~# cat /etc/pve/lxc/104.conf
arch: amd64
cores: 2
features: nesting=1
hostname: server
memory: 4096
mp0: /mnt/lxc_shares/qrCodeImage,mp=/opt/genedatabank/qrCodeImage
nameserver: 192.168.9.254 8.8.8.8
net0: name=eth0,bridge=vmbr2,gw=192.168.9.254,hwaddr=00:00:00:00:00:00,ip=192.168.9.5/24,type=veth
onboot: 1
ostype: ubuntu
rootfs: local-lvm:vm-104-disk-0,size=250G
startup: order=2,up=20
swap: 4096
unprivileged: 1
mp1: /mnt/lxc_shares/Backup_GeneDataBank,mp=/opt/genedatabank/Backup_GeneDataBank
The trick, is necessary to add in pve host at fstab for gid=100000+gid_from_lxc group in my case for genedatabank group from lxc what have 987 I add 100987 in fstab from PVE
florin@server:~$ grep genedatabank /etc/group
genedatabank:x:987:genedatabank
lxc_shares:x:10000:genedatabank
I used the tutorial but I understood the trick and leave lxc_shares group for the future needs.