Mounting Image on 2.5.27 work on Debian?

System: Debian Bullseye, btrfs, dedup

after klick on mount via Web-Interface … Urbackup hangs … (also after 2 hours)
urbackup-fuse.log looks ok …no error … last message “Volume offset is …”

/var/log/message
Dec 15 11:53:57 storage3 kernel: [1311188.049155] mnt image[30437]: segfault at 31 ip 0000000000575e4f sp 00007f2e477fc230 error 4 in urbackupsrv[400000+91b000]
Dec 15 11:53:57 storage3 kernel: [1311188.049196] Code: 28 00 00 00 75 5f 48 81 c4 18 10 00 00 5b 5d 41 5c 41 5d c3 0f 1f 80 00 00 00 00 49 8b 45 00 31 d2 49 89 d8 4c 89 e1 4c 89 ef <48> 8b 70 e8 e8 08 c2 5f 00 48 81 fb 00 10 00 00 74 92 eb ad 0f 1f
^C

root@storage3:/etc/init.d# ./urbackupsrv status
● urbackupsrv.service - LSB: Server for doing backups
Loaded: loaded (/etc/init.d/urbackupsrv; generated)
Active: active (running) since Wed 2022-11-30 07:41:01 CET; 2 weeks 1 days ago
Docs: man:systemd-sysv-generator(8)
Process: 768 ExecStart=/etc/init.d/urbackupsrv start (code=exited, status=0/SUCCESS)
Tasks: 6 (limit: 18694)
Memory: 981.6M
CPU: 10h 32min 25.223s
CGroup: /system.slice/urbackupsrv.service
├─30445 /usr/bin/urbackupsrv mount-vhd -f /urbackup/XXXXXX1/221214-2040_Image_C/Image_C_221214-2040.vhdz -m /urbacku…
├─31291 /usr/bin/qemu-system-x86_64 -global virtio-blk-pci.scsi=off -no-user-config -enable-fips -nodefaults -display…
└─31310 guestmount -r --format=raw -a /urbackup/XXXXXX/221214-2040_Image_C/device0/volume -o uid=117,gid=125,allow_…

/var/log/urbackup.log … no error

could the problem be that Urbackup-Server is a VM (kvm)?

i activated nested kvm … same problem…

but this looks interresting:

root@storage3:/urbackup/XXXXXX/221214-2040_Image_C# ls -la
ls: Zugriff auf ‘contents0’ nicht möglich: Keine Berechtigung
ls: Zugriff auf ‘device0’ nicht möglich: Keine Berechtigung
insgesamt 285124
drwxr-x— 1 urbackup urbackup 316 15. Dez 17:59 .
drwxr-x— 1 urbackup urbackup 3584 14. Dez 20:40 …
d??? ? ? ? ? ? contents0
d??? ? ? ? ? ? device0
-rwxr-x— 1 urbackup urbackup 279504244 14. Dez 20:41 Image_C_221214-2040.vhdz
-rwxr-x— 1 urbackup urbackup 4139500 14. Dez 20:40 Image_C_221214-2040.vhdz.cbitmap
-rwxr-x— 1 urbackup urbackup 8278944 14. Dez 20:41 Image_C_221214-2040.vhdz.hash
-rwxr-x— 1 urbackup urbackup 34396 14. Dez 20:40 Image_C_221214-2040.vhdz.mbr
-rwxr-x— 1 urbackup urbackup 0 14. Dez 20:41 Image_C_221214-2040.vhdz.sync

sorry for the german copy/paste … this means … no permission to access contents0