HAS disaster recovery instructions, restore from which backup file?

Configuration
1

The original problem

My HAS installation was bricked by latest update. Basically, I have an non-bootable HAS OS installation running on VirtualBox. Already tried to look at random text in rescue mode (pointless exercise :P) but there are other complications that prevent me from actually trying to fix the install, probably related to [link].

The plan to fix

After failing miserably at root causing and fixing the issue I decided to start from scratch. Even though the system won’t boot I mounted the .vdi file and I can look at all config and backup files from the prior system.

The real problem

There is tons of documentation/blogs/questions (web actually flooded with the stuff) around “how to create backup”, “how to create off-site copies”, there are basic instructions on how to “restore from backup”… but I am unable to find the answer to the most basic question: which backup file do I even choose? There are probably 100+ files ranging in all sizes:

[root@nuk supervisor]# ls -l -t --block-size=M backup/
total 4138M
-rw-r--r-- 1 root root    1M Feb 26 21:03 10bef746.tar
…
-rw-r--r-- 1 root root   53M Feb 26 20:53 2d721b1b.tar
…
-rw-r--r-- 1 root root    1M Feb 11 17:14 22821064.tar
…
-rw-r--r-- 1 root root  102M Nov 26 21:26 b451e8aa.tar
…
-rw-r--r-- 1 root root 1118M Jul 23  2023 13476736.tar

Questions

  • Should I choose the largest (1GB) from seven months ago? Already forgot what incremental changes I made to replicate again.
  • How about the 1MB file created right before the crash? That sounds utterly useless.
  • 50-100MB files? More promising, but what even are they? how do they compare to the rest of the “backups”?
  • Should I restore all 100+ backups incrementally to “build up” the latest state of my prior HAS?

I know there is a difference between “partial backup” and “full backup”, but there is saturation on related topics that makes it hard to even find what is a partial backup [link]:

  • What does it include?
  • What happens if I restore from partial backup?
  • How do I tell partial from full when when looking at an endless list of tar files?
2

This actually sheds some light on the potential solution [link], apparently “restoring from partial backup” is possible, but honestly doesn’t clear a lot of my questions.

Edit: The most recent 50MB file was a partial backup, containing most (if not all) prior config. I did have to re-install addons like Zigbee2MQTT, mosquito broker, ESPHome. However, looks like configuration was also retained for those addons. For now I will say this was a successful recovery :slight_smile: