Backup error when args: -vnc is used.

[ozgurerdogan]

Some vms have:

args: -vnc 0.0.0.0:01 for vnc connection as stated https://pve.proxmox.com/wiki/VNC_Client_Access


But when backing up these vms by pbs, I got:
INFO: creating Proxmox Backup Server archive 'vm/3230/2025-04-11T00:50:21Z'
INFO: starting kvm to execute backup task
kvm: -vnc 0.0.0.0:01: Failed to find an available port: Address already in use
ERROR: start failed: QEMU exited with code 1
INFO: aborting backup job
ERROR: VM 3230 not running
VM 3230 not running
ERROR: Backup of VM 3230 failed - start failed: QEMU exited with code 1


How can I configure persistent external VNC access without using the args: -vnc 0.0.0.0:01 line?
This line causes conflicts during backup, so I'm looking for a cleaner method that doesn't interfere with Proxmox Backup Server.


Any advise?

 

[Chris]

Hi,

kvm: -vnc 0.0.0.0:01: Failed to find an available port: Address already in use

this error states that the port you have configured for your VNC access is already in use by another instance. I guess you are using the same port for multiple VMs? And since the VM needs to be executed in order to create the backup, the VM start fail.

I would advice to configure different ports for your VMs so you will have no conflict and the backups will work just fine.

 

[ozgurerdogan]

Yes there are only two vms one with args: -vnc 0.0.0.0:01 and second with args: -vnc 0.0.0.0:02

 

[Chris]

Please post the output of cat /etc/pve/jobs.conf and the VM config for both VMs via qm config <VMID> --current, replacing the VMID with the corresponding values.

 

[ozgurerdogan]

Thank you.

root@s1:~# cat /etc/pve/jobs.cfg
vzdump: backup-da995aca-3015
        schedule *-*-01 01:00:00
        compress zstd
        enabled 0
        fleecing 0
        mailnotification failure
        mailto mail@domain.com
        mode snapshot
        notes-template {{guestname}}
        performance max-workers=1
        storage Pbsm-ZFSD1
        vmid 3230,3460,3410,3370,3320,3310,2720,2580,2540,2480,2470,2440,1930,1790,1450




root@s1:~# qm config 3230 --current
agent: 1,fstrim_cloned_disks=1
args: -vnc 0.0.0.0:01
balloon: 12000
boot: order=scsi0
cores: 12
machine: pc-i440fx-7.1
memory: 18432
meta: creation-qemu=7.1.0,ctime=1676305266
name: xxx.xxx.com
net0: virtio=BC:24:11:9E:39:27,bridge=vmbr0
numa: 0
onboot: 1
ostype: win11
scsi0: D4:vm-323-disk-0,discard=on,size=300G,ssd=1
scsihw: virtio-scsi-single
smbios1: uuid=fc77bf69-938f-4cec-a84a-d74b0b8b547a
sockets: 1
tablet: 0
vmgenid: b7488258-ce05-4d76-90e9-d4eb75016629


root@s1:~# qm config 3370 --current
agent: 1,fstrim_cloned_disks=1
args: -vnc 0.0.0.0:02
balloon: 18528
boot: order=scsi0
cores: 8
machine: pc-i440fx-7.1
memory: 22528
meta: creation-qemu=7.1.0,ctime=1676305266
name: xxx.xxx.com
net0: virtio=BC:24:11:3F:68:66,bridge=vmbr0
numa: 0
onboot: 1
ostype: win11
scsi0: D2:vm-337-disk-0,discard=on,size=400G,ssd=1
scsihw: virtio-scsi-single
smbios1: uuid=26c19ee8-7f69-4d17-88fd-2533bc4046e6
sockets: 1
tablet: 0
vmgenid: 85273ef1-4442-46ce-832d-b8569acfcc45

No more wm with args: -vnc...