Backups
Offsite backup storage: why separation matters
Offsite backup storage exists to create a recovery path that does not share every failure with production. The exact meaning of “offsite” depends on the risk you are separating from: one disk, one server, one account, one facility, or one provider.
Redundant disks protect availability, not history
RAID or mirrored storage can keep a system running after some hardware failures, but deletion, ransomware, corrupted writes, administrator mistakes, and application bugs can be copied to every redundant disk.
Snapshots are useful but can share control-plane risk
Provider snapshots can make fast rollback convenient. If the same compromised account can delete the server and every snapshot, they are not the only independent recovery copy you should rely on for critical data.
File synchronization can synchronize damage
A sync service is useful for collaboration and additional copies, but immediate synchronization can replicate deletion or encryption. Version history and independent retention are what turn another copy into stronger recovery protection.
Choose separation based on the failure you must survive
For some workloads, another server in the same provider is enough for an operational copy. Higher-value data may justify separate accounts, regions, providers, offline media, or immutable retention according to the threat and recovery requirements.