A rolling upgrade individually upgrades and restarts each node in the cluster sequentially. During a rolling upgrade, the cluster remains online and continues serving data to clients with no interruption in service. Before OneFS 8.0, a rolling upgrade could only be performed within a OneFS code version family and not between OneFS major code version revisions. Beginning with OneFS 8.0, every new release is rolling-upgradable from the previous version. The OneFS upgrade image is cryptographically signed, allowing independent verification that software being installed has not been tampered with.