Yesterday i released a new version of virtnbdbackup with a nice improvement.

The new version can now detect zeroed regions in the bitmaps by comparing the block regions against the state within the base bitmap during incremental backup.

This is helpful if virtual machines run fstrim, as it results in less backup footprint. Before the incremental backups could grow the same amount of size as fstrimmed data regions.

I also managed to enhance the tests by using the arch linux cloud images. The automated github CI tests now actually test backup and restores against a virtual machine running an real OS.