backup only unprivileged container failed

[BAfH]

Hello,

the original post see here
here is my problem.
Use Proxmox with one Backup Share on my OpenMediaVault as a NFS Share.
3 LXC container
* 101 pihole priviliged
* 103 NextCloud unpriviliged
use a CIFS Share on my OpenMediaVault for Data
* 105 Jellyfin unpriviliged
2 VM
* 100 Ubuntu with Docker FHEM;MYSQL,ZigBee2MQTT ...
* 104 Home Assistant

i use only one Backup job
only 103 Nextcloud has a error.

/etc/fstab

#Backup Mount vom NAS
192.168.10.3:/Backup  /mnt/pve/NASBackupNeu  nfs  defaults 0 0
#Mount Media for jellyfin LXC 105
192.168.10.3:/  /mnt/media  nfs  defaults 0 0
#Mount Nextcloud for nextcloud LXC 103
//192.168.10.3/Nextcloud /mnt/nextcloud cifs _netdev,x-systemd.automount,noatime,uid=100033,gid=100033,dir_mode=0770,file_mode=0770,,credentials=/home/.smbcredentials 0 0

i give the mountingpoint to my LXC container

pct set 103 -mp0 /mnt/nextcloud/,mp=/var/www/html/data

Backup Job failed

INFO: starting new backup job: vzdump 103 --mode snapshot --prune-backups 'keep-weekly=2' --compress zstd --storage NASBackup --fleecing 0 --node pve --notes-template '{{guestname}}' --all 0
INFO: Starting Backup of VM 103 (lxc)
INFO: Backup started at 2024-10-16 11:50:24
INFO: status = running
INFO: CT Name: NextCloud
INFO: including mount point rootfs ('/') in backup
INFO: excluding bind mount point mp0 ('/var/www/html/data/') from backup (not a volume)
INFO: backup mode: snapshot
INFO: ionice priority: 7
INFO: create storage snapshot 'vzdump'
  Logical volume "snap_vm-103-disk-0_vzdump" created.
INFO: creating vzdump archive '/mnt/pve/NASBackupNeu/dump/vzdump-lxc-103-2024_10_16-11_50_24.tar.zst'
INFO: tar: ./var/spool/rsyslog: Cannot open: Permission denied
INFO: tar: ./var/cache/private: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/684a20eb.0/sbin.dhclient-aWE9TC: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/684a20eb.0/lsb_release-L4zL5g: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/684a20eb.0/ubuntu_pro_esm_cache-owaSvo: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/684a20eb.0/lsb_release-Z59yI5: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/684a20eb.0/usr.bin.man-02l8ra: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/684a20eb.0/sbin.dhclient-rj2oMT: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/684a20eb.0/ubuntu_pro_apt_news-6AH71t: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/684a20eb.0/ubuntu_pro_esm_cache-SDvqjN: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/684a20eb.0/ubuntu_pro_apt_news-7EK3gM: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/684a20eb.0/usr.bin.tcpdump-O0iFrN: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/684a20eb.0/usr.bin.tcpdump-bP0IQf: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/684a20eb.0/usr.bin.man-AwlDt4: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/684a20eb.0/nvidia_modprobe-9Xy4cr: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/684a20eb.0/nvidia_modprobe-0OjfFx: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/nvidia_modprobe-Ei4n8U: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/lsb_release-7bACw4: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/usr.bin.tcpdump-sqbjwq: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/ubuntu_pro_apt_news-3wyiTk: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/usr.bin.man-hjFm8f: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/nvidia_modprobe-7iWaDC: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/ubuntu_pro_esm_cache-HslwAl: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/ubuntu_pro_esm_cache-nHVJm3: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/usr.bin.man-rIgsYb: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/lsb_release-CKavPZ: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/usr.bin.man-7rE5Qj: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/usr.bin.man-OsHa4J: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/usr.bin.tcpdump-fexP61: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/nvidia_modprobe-R549fF: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/ubuntu_pro_apt_news-RkXyXv: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/ubuntu_pro_apt_news-K3hGNu: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/ubuntu_pro_esm_cache-CFxRWw: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/sbin.dhclient-02ythu: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/nvidia_modprobe-SQsKqg: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/ubuntu_pro_esm_cache-JKe2PA: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/lsb_release-MdTGeW: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/lsb_release-7nuya2: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/sbin.dhclient-2TKQYd: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/sbin.dhclient-sFPbgP: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/usr.bin.man-jK5N3I: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/sbin.dhclient-UUl0Zk: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/usr.bin.tcpdump-2xNdpu: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/usr.bin.tcpdump-35hBmW: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/nvidia_modprobe-y4FihN: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/lsb_release-LWutDP: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/nvidia_modprobe-GlIL4J: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/usr.bin.man-inr9b0: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/lsb_release-PDXiK8: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/ubuntu_pro_esm_cache-MxE3Nd: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/usr.bin.tcpdump-yLOl7j: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/sbin.dhclient-Jm9YOR: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/ubuntu_pro_apt_news-MY8Rg4: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/ubuntu_pro_apt_news-CfdCTq: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/ubuntu_pro_esm_cache-mezNjF: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/usr.bin.tcpdump-BTyrFu: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/ubuntu_pro_apt_news-eKYWfm: Cannot open: Permission denied
INFO: tar: ./var/cache/apparmor/7a03f264.0/sbin.dhclient-NReWQt: Cannot open: Permission denied
INFO: tar: ./var/lib/private: Cannot open: Permission denied
INFO: tar: ./var/log/btmp: Cannot open: Permission denied
INFO: tar: ./var/log/mail.err: Cannot open: Permission denied
INFO: tar: ./var/log/private: Cannot open: Permission denied
INFO: Total bytes written: 4434565120 (4.2GiB, 48MiB/s)
INFO: tar: Exiting with failure status due to previous errors
INFO: cleanup temporary 'vzdump' snapshot
  Logical volume "snap_vm-103-disk-0_vzdump" successfully removed.
ERROR: Backup of VM 103 failed - command 'set -o pipefail && lxc-usernsexec -m u:0:100000:65536 -m g:0:100000:65536 -- tar cpf - --totals --one-file-system -p --sparse --numeric-owner --acls --xattrs '--xattrs-include=user.*' '--xattrs-include=security.capability' '--warning=no-file-ignored' '--warning=no-xattr-write' --one-file-system '--warning=no-file-ignored' '--directory=/tmp/vzdumptmp2305694_103/' ./etc/vzdump/pct.conf ./etc/vzdump/pct.fw '--directory=/mnt/vzsnap0' --no-anchored '--exclude=lost+found' --anchored '--exclude=./tmp/?*' '--exclude=./var/tmp/?*' '--exclude=./var/run/?*.pid' ./ | zstd '--threads=1' >/mnt/pve/NASBackupNeu/dump/vzdump-lxc-103-2024_10_16-11_50_24.tar.dat' failed: exit code 2
INFO: Failed at 2024-10-16 11:51:55
INFO: Backup job finished with errors
TASK ERROR: job errors

Why i use an Share on my OMV für data on Nextcloud?
So, my idea was, on OMV i have 2 datastore on differnet Disk:
* Nextcloud
* NextcloudBackup
every day, a rsync job duplicate data from Nextcloud to Nextcloudbackup

at the moment i'm standing in the forest and can't find my way out
thanks