Split the catalog cache
Today the catalog caches a few things:
- the list of configured remotes
- the list of packages available in each remote
- the downloaded package files
- the list of installed packages
Items 2 and 3 are clearly cache: if they get dropped, then they can be obtained again by updating the cache of the catalog or redownloading the package(s).
However, items 1 and 4 are really local data, and as such they would need to be backed up. This way, we could only backup the fact that a package is installed and not the actual contents, and when restoring from a backup we'd just have to reinstall the package.
So we need to split the current catalog cache, and move some of it to BACKUPED_ROOT
.