What is LBU?

Alpine Linux has a cool feature called LBU that lets you create a backup on top of the Live ISO. These backups are called local backups.

I plan on using LBU as a system maintenance drive. It allows you to save changes you make to the Live ISO and restore them automatically when you boot the next time.

Setup and Committing

To set up LBU I booted the Alpine Linux ISO, ran setup-alpine, mounted my drive to /media/alpine_usb and when I got to the disk selection I selected no disk, and alpine_usb as where to store the configs, and the default for cache.

Now when I make changes in the Alpine Linux Live ISO I can commit them.

To see what is being committed I first check lbu status which lists all the files being added or removed, then lbu commit to commit the changes.

When I was rebooting I had an issue where the drive would automount itself to /media/sdb and then wouldn’t work with lbu when I wanted to commit or check the status because it was already mounted. To fix this I just had to umount /dev/sdb on boot and then lbu worked as expected.

Caching and Configuration

To use cache you have to mount it to /media/alpine_usb so that it can write the cache files when you’re installing packages. I want this because it makes reinstalling my packages on reboot a lot faster, they can just be loaded from cache instead of from online repositories.

Upon reboot I had to reinstall all the packages I had installed using apk upgrade but since the cache is there it just installs everything really quickly.

I uncommented and changed the number of backups in /etc/lbu/lbu.conf to 20 so that I would be able to revert up to 20 commits in case I broke my configs.

I see Alpine LBU as a good way to keep a backup of changes to the ISO so it could be used as a system recovery disk with the tools that are needed.