Hi,
I found out that when a container is stopped the backup is doing a 'stopped' mode backup as well it's configured to snapshot. Now I can start the container while the backup is running. After that there is R/W action on the container file system which makes the backup inconsistent. If you are lucky the backup script figures out it's failure (like in the log below).
Note: Backup type is snapshot. So the solution should be either to use snapshot mode as well on stopped containers or lock it while backup.
NFO: Starting Backup of VM 208 (lxc)
INFO: status = stopped
INFO: backup mode: stop
INFO: bandwidth limit: 51200 KB/s
INFO: ionice priority: 7
INFO: creating archive '/mnt/pve/FreeNAS/dump/vzdump-lxc-208-2015_12_12-12_37_32.tar.lzo'
INFO: tar: ./var/www/owncloud/data/owncloud.log: file changed as we read it
INFO: tar: ./var: file changed as we read it
INFO: tar: .: file changed as we read it
INFO: Total bytes written: 12971069440 (13GiB, 25MiB/s)
ERROR: Backup of VM 208 failed - command 'set -o pipefail && tar cpf - --totals --sparse --numeric-owner --acls --xattrs '--xattrs-include=user.*' '--xattrs-include=security.capability' '--warning=no-xattr-write' --one-file-system '--warning=no-file-ignored' '--directory=/tmp/vzdumptmp26953' ./etc/vzdump/pct.conf ./etc/vzdump/pct.fw '--directory=/mnt/vzsnap0' --no-anchored '--exclude=lost+found' --anchored ./ | cstream -t 52428800 | lzop >/mnt/pve/FreeNAS/dump/vzdump-lxc-208-2015_12_12-12_37_32.tar.dat' failed: exit code 1
root@ckc-b-p0005:~# pveversion -v
proxmox-ve: 4.1-26 (running kernel: 4.2.6-1-pve)
pve-manager: 4.1-1 (running version: 4.1-1/2f9650d4)
pve-kernel-4.2.6-1-pve: 4.2.6-26
pve-kernel-4.2.2-1-pve: 4.2.2-16
pve-kernel-4.2.3-2-pve: 4.2.3-22
lvm2: 2.02.116-pve2
corosync-pve: 2.3.5-2
libqb0: 0.17.2-1
pve-cluster: 4.0-29
qemu-server: 4.0-41
pve-firmware: 1.1-7
libpve-common-perl: 4.0-41
libpve-access-control: 4.0-10
libpve-storage-perl: 4.0-38
pve-libspice-server1: 0.12.5-2
vncterm: 1.2-1
pve-qemu-kvm: 2.4-17
pve-container: 1.0-32
pve-firewall: 2.0-14
pve-ha-manager: 1.0-14
ksm-control-daemon: 1.2-1
glusterfs-client: 3.5.2-2+deb8u1
lxc-pve: 1.1.5-5
lxcfs: 0.13-pve1
cgmanager: 0.39-pve1
criu: 1.6.0-1
zfsutils: 0.6.5-pve6~jessie
I found out that when a container is stopped the backup is doing a 'stopped' mode backup as well it's configured to snapshot. Now I can start the container while the backup is running. After that there is R/W action on the container file system which makes the backup inconsistent. If you are lucky the backup script figures out it's failure (like in the log below).
Note: Backup type is snapshot. So the solution should be either to use snapshot mode as well on stopped containers or lock it while backup.
NFO: Starting Backup of VM 208 (lxc)
INFO: status = stopped
INFO: backup mode: stop
INFO: bandwidth limit: 51200 KB/s
INFO: ionice priority: 7
INFO: creating archive '/mnt/pve/FreeNAS/dump/vzdump-lxc-208-2015_12_12-12_37_32.tar.lzo'
INFO: tar: ./var/www/owncloud/data/owncloud.log: file changed as we read it
INFO: tar: ./var: file changed as we read it
INFO: tar: .: file changed as we read it
INFO: Total bytes written: 12971069440 (13GiB, 25MiB/s)
ERROR: Backup of VM 208 failed - command 'set -o pipefail && tar cpf - --totals --sparse --numeric-owner --acls --xattrs '--xattrs-include=user.*' '--xattrs-include=security.capability' '--warning=no-xattr-write' --one-file-system '--warning=no-file-ignored' '--directory=/tmp/vzdumptmp26953' ./etc/vzdump/pct.conf ./etc/vzdump/pct.fw '--directory=/mnt/vzsnap0' --no-anchored '--exclude=lost+found' --anchored ./ | cstream -t 52428800 | lzop >/mnt/pve/FreeNAS/dump/vzdump-lxc-208-2015_12_12-12_37_32.tar.dat' failed: exit code 1
root@ckc-b-p0005:~# pveversion -v
proxmox-ve: 4.1-26 (running kernel: 4.2.6-1-pve)
pve-manager: 4.1-1 (running version: 4.1-1/2f9650d4)
pve-kernel-4.2.6-1-pve: 4.2.6-26
pve-kernel-4.2.2-1-pve: 4.2.2-16
pve-kernel-4.2.3-2-pve: 4.2.3-22
lvm2: 2.02.116-pve2
corosync-pve: 2.3.5-2
libqb0: 0.17.2-1
pve-cluster: 4.0-29
qemu-server: 4.0-41
pve-firmware: 1.1-7
libpve-common-perl: 4.0-41
libpve-access-control: 4.0-10
libpve-storage-perl: 4.0-38
pve-libspice-server1: 0.12.5-2
vncterm: 1.2-1
pve-qemu-kvm: 2.4-17
pve-container: 1.0-32
pve-firewall: 2.0-14
pve-ha-manager: 1.0-14
ksm-control-daemon: 1.2-1
glusterfs-client: 3.5.2-2+deb8u1
lxc-pve: 1.1.5-5
lxcfs: 0.13-pve1
cgmanager: 0.39-pve1
criu: 1.6.0-1
zfsutils: 0.6.5-pve6~jessie
