[SOLVED] [Backup & Restore] How to create a CT from an existing volume (disk-image)

[francoisd]

Concern: Backup & Restore

I restored a volume (from ceph RBD), and want to start a CT from it.
How should I create & start a CT from which I have the disk image ?

Preferably without re-creating the /etc/pve/nodes/{node}/lxc/{vmid}.conf config file from an existing one. (Consider I lost the original one).
The volume is visible with pvesm list {storage}:

root@pve2:~# pvesm list cephblock | grep 198
cephblock:vm-198-disk-0 raw     images     4294967296 198

Thanks,

 

[fabian]

you need to create the config file and then add that volume as 'rootfs'.. or alternatively, create a template from the volume (mount it, create a tar archive), then pass that to pct create).

 

[francoisd]

Thanks Fabian,
Just created the <vmid>.conf (with an unused vmid), and it worked. Just a bit odd that we can't do it from the GUI or pvesh.

root@pve1:/# cat /etc/pve/nodes/pve1/lxc/198.conf
arch: amd64
cores: 1
features: nesting=1
hostname: ubutst1
memory: 512
net0: name=eth0,bridge=vmbr0,firewall=1,gw=192.168.10.1,hwaddr=42:C1:57:0D:52:69,ip=192.168.10.74/24,tag=10,type=veth
ostype: ubuntu
rootfs: cephblock:vm-198-disk-0,size=4G
swap: 512
unprivileged: 1

I kept the same IP/hwaddr from original.

The CT is running, and contains all the restored data from base image export and all subsequent diff-exports.

So, a backup of the /etc/pve/nodes might be of good value in case of DR. Just added:

root@pve1:/# cat /etc/cron.daily/backup_pve_config.sh
#!/bin/sh
tar -Jc /etc/pve/nodes | rclone --config /etc/rclone/rclone.conf rcat OneDriveSecure1:/pvesnapshot/etc_pve_nodes_$(date -I).tar.xz

I'm currently working on a python script to remote backup volumes to an rclone destination, with daily diff/incremental exports from snapshots & snapshot autoclean.

 

[fabian]

well usually you'd do a backup and restore a container must have a rootfs, so creating a container without one is not possible over the API. and importing arbitrary file systems is rather dangerous, so that is not offered over the API either.