First - Backups! Proper backups make a huge difference in the damage these attacks can do. Second - Copy on write file systems like BTRFS and ZFS further mitig

First - Backups! Proper backups make a huge difference in the damage these attacks can do. Second - Copy on write file systems like BTRFS and ZFS further mitigate things when setup to retain snapshots/checkpoints of past data on disk. Since these can’t be modified by subsequent writing of encrypted data preventing ransomware from locking you out of your data.