I am trying to devise a backup strategy for a Windows server, and I'd like it to satisfy the following criteria:
- It should be resilient to malware: If ransomware takes over the server, it should not be able to destroy the backup.
- It should be automatic, i.e., it should not rely on people manually attaching and removing USB HDDs.
- It should be as simple as possible given the two criteria above.
This is what I have already thought of:
Automatic nightly backup to some external storage: not malware-resilient. The server needs write access to the storage; thus, the storage can be wiped once the server has been compromised.
Automatic nightly backup to rotating USB disks which are stored externally: not automatic, since it depends on humans not forgetting to do that.
Automatic nightly backup to rotating USB disks which are switched by a robot: not simple.
Automatic nightly backup to the cloud using Azure backup: not malware-resilient.
Another option would be a backup server which pulls backups from the main server, but I guess harding the backup server such that the main server has no access to it (even if the malware gains domain admin access) qualifies as not simple.
Any other option that I've overlooked?