Backup fails with org.freedesktop.DBus.Error.Disconnected: Connection is closed

[hello]

Hi there,

I'm doing weekly backups and every time I get a bunch of errors.

I can see a pattern. Backups fail only on virtual machines that are powered off.

It's a stand alone node.

Does anybody knows anything about this problem?

Thanks.

Here is the relevant log excerpt:

116: 2020-10-17 10:48:14 INFO: Starting Backup of VM 116 (qemu)
116: 2020-10-17 10:48:14 INFO: status = stopped
116: 2020-10-17 10:48:14 INFO: backup mode: stop
116: 2020-10-17 10:48:14 INFO: ionice priority: 7
116: 2020-10-17 10:48:14 INFO: VM Name: myvm
116: 2020-10-17 10:48:14 INFO: include disk 'scsi0' 'zfs:vm-116-disk-0' 20G
116: 2020-10-17 10:48:14 INFO: creating vzdump archive '/zfs_mybook/backup//dump/vzdump-qemu-116-2020_10_17-10_48_14.vma.zst'
116: 2020-10-17 10:48:14 INFO: starting kvm to execute backup task
116: 2020-10-17 10:48:14 ERROR: Backup of VM 116 failed - start failed: org.freedesktop.DBus.Error.Disconnected: Connection is closed

and here are my software versions:

# pveversion --verbose
proxmox-ve: 6.2-2 (running kernel: 5.4.65-1-pve)
pve-manager: 6.2-12 (running version: 6.2-12/b287dd27)
pve-kernel-5.4: 6.2-7
pve-kernel-helper: 6.2-7
pve-kernel-5.3: 6.1-6
pve-kernel-5.4.65-1-pve: 5.4.65-1
pve-kernel-5.4.60-1-pve: 5.4.60-2
pve-kernel-5.3.18-3-pve: 5.3.18-3
ceph-fuse: 12.2.11+dfsg1-2.1+b1
corosync: 3.0.4-pve1
criu: 3.11-3
glusterfs-client: 5.5-3
ifupdown: 0.8.35+pve1
libjs-extjs: 6.0.1-10
libknet1: 1.16-pve1
libproxmox-acme-perl: 1.0.5
libpve-access-control: 6.1-3
libpve-apiclient-perl: 3.0-3
libpve-common-perl: 6.2-2
libpve-guest-common-perl: 3.1-3
libpve-http-server-perl: 3.0-6
libpve-storage-perl: 6.2-9
libqb0: 1.0.5-1
libspice-server1: 0.14.2-4~pve6+1
lvm2: 2.03.02-pve4
lxc-pve: 4.0.3-1
lxcfs: 4.0.3-pve3
novnc-pve: 1.1.0-1
proxmox-backup-client: 0.9.1-1
proxmox-mini-journalreader: 1.1-1
proxmox-widget-toolkit: 2.3-1
pve-cluster: 6.2-1
pve-container: 3.2-2
pve-docs: 6.2-6
pve-edk2-firmware: 2.20200531-1
pve-firewall: 4.1-3
pve-firmware: 3.1-3
pve-ha-manager: 3.1-1
pve-i18n: 2.2-1
pve-qemu-kvm: 5.1.0-3
pve-xtermjs: 4.7.0-2
qemu-server: 6.2-15
smartmontools: 7.1-pve2
spiceterm: 3.1-1
vncterm: 1.6-2
zfsutils-linux: 0.8.4-pve2

 

[wolfgang]

Hi,

this is because you have installed udisks2 on your host and this demon overwhelmed the DBus.

 

[hello]

Hi wolfgang. The package udisks2 isn't installed on this server.

 

[wolfgang]

There could also other packages that overwhelmed the DBus.
In a plain Proxmox VE installation this should not the case.

 

[marcbe]

There could also other packages that overwhelmed the DBus.
In a plain Proxmox VE installation this should not the case.

I have the same problem (proxmox 6.3.3), but only if the backup works scheduled, if I do the backup manually it works. (I tested backup "standard" and proxmox backup server 1.0-6 with the same results).

how would you proceed to identify the cause?

Also in my case I don't have udisks2, I didn't do anything after installing, upgrading and using it.

 

[fiona]

Hi,

I have the same problem (proxmox 6.3.3), but only if the backup works scheduled, if I do the backup manually it works. (I tested backup "standard" and proxmox backup server 1.0-6 with the same results).

how would you proceed to identify the cause?

Also in my case I don't have udisks2, I didn't do anything after installing, upgrading and using it.

could you share the VM configurations of one or two affected VMs (qm config <ID>) and the vzdump parameters (cat /etc/cron.d/vzdump)?

EDIT: even better if you could also monitor the dbus around the time the scheduled backup runs, with dbus-monitor --system --profile &> /tmp/dbuslogfile. But best to keep track of it, because it might get large quickly if there is a lot going on on the dbus.