Patent ID: 11861340
Assignee: NETAPP, INC.
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 12:
13. A non-transitory computer-readable storage medium embodying a set of instructions, which when executed by one or more processing resources cause the one or more processing resources to:
implement a multi-tiered file system in a storage node, the multi-tiered filesystem having an on-disk layout that segregates a base configuration of an operating system of the storage node from runtime data associated with the operating system, containing modifications to the base configuration, the multi-tiered file system comprising (i) a read-only layer that contains the base configuration for the storage node including an image of a first version of the operating system and (ii) a read-write layer that contains the runtime data;
upgrade the first version of the operating system to a second version of the operating system without requiring a root partition of a boot disk of the storage node to be recreated by:
combining the read-only layer and the read-write layer into an overlay filesystem that is presented to the operating system as the root partition; and
configuring the storage node to use a new image of the second version of the operating system in place of the image stored on the root partition; and
performing a soft reboot to cause a return to factory image (RTFI) process to install the second version of the operating system via the overlay filesystem without modifying the read-write layer.