FMADIO LXC is structured such that all files for the LXC are contained within the directory structure of the container.
/opt/fmadio/lxc/<container name>/
This enables a simple tarball to be generated of the directory, similarly restoring that tarball on the same system, on a different system is straight forward. By tarballing the LXC directory above. It creates a simple and robust way to manage LXC containers.
The filename naming scheme of backups is:
<container name>-backup-YYYYMMDD-HHMM.tar.gz
Example:
fmadio@fmadio200v4-636:/opt/fmadio/lxc$ ls -al *backup*
-rw-r--r-- 1 root root 771946353 Oct 9 04:18 pcap2dns-20241002-0604-backup-20241009-0416.tar.gz
-rw-r--r-- 1 root root 721641207 Oct 3 11:07 pcap2dns-20241003-0935-backup-20241003-1106.tar.gz
fmadio@fmadio200v4-636:/opt/fmadio/lxc$This can be used for backup of the container and also used as a distribution / install packaging approach for a container.
Backup the LXC Container
Step 1) Ensure the LXC Container is shutdown
Check the status
sudo lxc-ls -fExample output is
fmadio@fmadio200v4-636:~$ sudo lxc-ls -f
NAME STATE AUTOSTART GROUPS IPV4 IPV6 UNPRIVILEGED
pcap2dns-20240611-0523 STOPPED 0 - - - false
pcap2dns-20240827-0525 STOPPED 0 - - - false
pcap2dns-20241002-0604 STOPPED 0 - - - false
pcap2dns-20241007-1033 RUNNING 0 - 192.168.255.30 - false
pcap2json-202402091423 STOPPED 0 - - - false
ubuntu22-202312061042 STOPPED 0 - - - false
fmadio@fmadio200v4-636:~$In the above example the LXC pcap2dns-20241007-1033 which we want to backup is in the RUNNING state.
To shutdown the container run the command
sudo lxc-stop -n <container name>
For example in the above example to power down LXC pcap2dns-20241007-1033 as the following
fmadio@fmadio200v4-636:~$ sudo lxc-stop -n pcap2dns-20241007-1033
fmadio@fmadio200v4-636:~$Then check the container state is stopped
fmadio@fmadio200v4-636:~$ sudo lxc-ls -f
NAME STATE AUTOSTART GROUPS IPV4 IPV6 UNPRIVILEGED
pcap2dns-20240611-0523 STOPPED 0 - - - false
pcap2dns-20240827-0525 STOPPED 0 - - - false
pcap2dns-20241002-0604 STOPPED 0 - - - false
pcap2dns-20241007-1033 STOPPED 0 - - - false
pcap2json-202402091423 STOPPED 0 - - - false
ubuntu22-202312061042 STOPPED 0 - - - false
fmadio@fmadio200v4-636:~$Step 2) Run the backup
Backup uses the command
lxc_backup.lua <container name>
Optionally a path for the tarball can be specified
lxc_backup.lua <container name> <path to write tarball>
By default backups are stored in
/opt/fmadio/lxc/
In our example to backup LXC pcap2dns-20241007-1033 run the following command. This may take several minutes to run depending on the disk usage of the LXC container.
fmadio@fmadio200v4-636:~$ lxc_backup.lua pcap2dns-20241002-0604
fmad fmadlua Sep 7 2024 (/opt/fmadio/bin/fmadiolua /opt/fmadio/bin/lxc_backup.lua pcap2dns-20241002-0604 )
------------------------------------------------------
Backup Path: /opt/fmadio/lxc/
Backup TarBall Name: pcap2dns-20241002-0604-backup-20241009-0416.tar.gz
LXC Directory: /opt/fmadio/lxc/
LXC Name: pcap2dns-20241002-0604
Current Date: 20241009-0416
------------------------------------------------------
sudo tar -czvf /opt/fmadio/lxc//pcap2dns-20241002-0604-backup-20241009-0416.tar.gz /opt/fmadio/lxc/pcap2dns-20241002-0604/*
tar: Removing leading `/' from member names
/opt/fmadio/lxc/pcap2dns-20241002-0604/backup.lua
tar: Removing leading `/' from hard link targets
2.27GiB 0:00:08 [ 265MiB/s] [ <=>
.
.
.
------------------------------------------------------
Backup File: /opt/fmadio/lxc//pcap2dns-20241003-0935-backup-20241009-0452.tar.gz
Backup Size: 721643872 (0.722 GB)
------------------------------------------------------
done 73.878011Sec 1.231300Min
fmadio@fmadio200v4-636:~$Step 3) Confirm the backup file
After the backup has completed, confirm the location and size of the file
In the above example the filename is:
pcap2dns-20241002-0604-backup-20241009-0452.tar.gz
With a total storage size of 736MB
fmadio@fmadio200v4-636:/opt/fmadio/lxc$ ls -alh /opt/fmadio/lxc/pcap2dns-20241002-0604-backup-20241009-0452.tar.gz
-rw-r--r-- 1 root root 736.2M Oct 9 04:18 /opt/fmadio/lxc/pcap2dns-20241002-0604-backup-20241009-0452.tar.gz
fmadio@fmadio200v4-636:/opt/fmadio/lxc$Restore LXC Container
Restoring the LXC container is quite straight forward. The following conditions are required
No container exists on the system with the same name
There is sufficient disk space
The tarball was created using the
lxc_backup.luacommand
To restore the container
Step 1) Run the Restore script
The restore script arguments are
lxc_restore.lua <location of tarball>
If no path is specified the default location of the tarball is
/opt/fmadio/lxc/
To restore the backup named
pcap2dns-20241003-0935-backup-20241003-1106.tar.gz
Run the following command
sudo lxc_restore.lua <container name backup tarball>Example output
fmadio@fmadio200v4-636:~$ lxc_restore.lua pcap2dns-20241003-0935-backup-20241003-1106.tar.gz
fmad fmadlua Sep 7 2024 (/opt/fmadio/bin/fmadiolua /opt/fmadio/bin/lxc_restore.lua pcap2dns-20241003-0935-backup-20241003-1106.tar.gz )
------------------------------------------------------
Restore Path: /opt/fmadio/lxc/pcap2dns-20241003-0935-backup-20241003-1106.tar.gz
Restore TarBall Name: pcap2dns-20241003-0935-backup-20241003-1106.tar.gz
LXC Directory: /opt/fmadio/lxc/
LXC Name: pcap2dns-20241003-0935
Current Date: 20241009-0439
------------------------------------------------------
Free Space on lxc directory 1.5T
Free Space on lxc directory in bytes: 1649267441664
Checking restore size.... please wait
------------------------------------------------------
Restore Size: 2857184276
sudo tar -xzf /opt/fmadio/lxc/pcap2dns-20241003-0935-0529-backup-20241016-0450.tar.gz -C / | pv -t
0:00:17
.
.
------------------------------------------------------
LXC restored: /opt/fmadio/lxc/pcap2dns-20241003-0935
------------------------------------------------------
done 12.840974Sec 0.214016Min
fmadio@fmadio200v4-636:~$Step 2) Confirm container is restored
Confirm the LXC Container has been restored using the lxc tools
sudo lxc-ls -f
Example output is:
fmadio@fmadio200v4-636:~$ sudo lxc-ls -f
NAME STATE AUTOSTART GROUPS IPV4 IPV6 UNPRIVILEGED
pcap2dns-20240611-0523 STOPPED 0 - - - false
pcap2dns-20240827-0525 STOPPED 0 - - - false
pcap2dns-20241002-0604 STOPPED 0 - - - false
pcap2dns-20241003-0935 STOPPED 0 - - - false
pcap2dns-20241007-1033 STOPPED 0 - - - false
pcap2json-202402091423 STOPPED 0 - - - false
ubuntu22-202312061042 STOPPED 0 - - - false
fmadio@fmadio200v4-636:~$In the above example we see the LXC container pcap2dns-20241003-0935 is present in the list.