Right now I am torn on what format to deploy my LXC disk images. Right now I think both ext4 and btrfs are good options.
ext4 is more tested, but btrfs sparse images are smaller then ext4 sparse images by a significant amount. My ext4 sparse base image is 1.8 GB but my btrfs base image with the same software minus the lost+found directory that was empty is only 1.1 GB. I could probably snapshot btrfs lxc images, but I would barely use it.
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