Hardware support for non-disruptive upgrades

A storage system, comprising:

• a first memory in each of a plurality of storage units of the storage system, configurable to contain configuration information;
• a solid-state memory in each of the plurality of storage units of the storage system, configurable for storage of user data;
• one or more processors in each of a plurality of storage nodes of the storage system, coupled to the plurality of storage units of the storage system and configurable to perform I/O (input/output) operations for the storage system, with each of the plurality of storage nodes to generate error correction coded data stripes and write the data stripes across the plurality of storage nodes, and each of the plurality of storage nodes configurable to perform an upgrade to the storage system by writing further configuration information to the first memory;
• hardware, firmware or one or more further processors in each of the plurality of storage units of the storage system, coupled to the first memory and the solid-state memory, configurable to have an interlock in the storage unit that disables and enables access by the one or more processors of the plurality of storage nodes to the first memory in the storage unit;
• the hardware, firmware or one or more further processors in each of the plurality of storage units further configurable to persist the configuration information in the first memory to the solid-state memory in the storage unit, responsive to a request for performing the upgrade and responsive to the interlock disabling the access by the one or more processors to the first memory, wherein at least persisting the configuration information is non-disruptive and performed under continuous supplied power;
• and
• an energy reserve configurable to support the hardware, firmware or one or more further processors, the first memory and the solid-state memory during power loss.

A tangible, non-transitory, computer-readable media having instructions thereupon which, when executed by a processor in a storage system, cause the processor to perform a method comprising:

• requesting the storage system to persist configuration information in a first memory in one of a plurality of storage units of the storage system to solid-state memory in the storage unit, with each of a plurality of storage nodes of the storage system coupled to the plurality of storage units of the storage system and with each of the plurality of storage nodes configurable to generate error correction coded data stripes and write the data stripes across the plurality of storage nodes, with the storage system:
• utilizing an interlock in the storage unit in response to the requesting, so that the interlock disables access by the processor, in one of the plurality of storage nodes of the storage system, to the first memory in the storage unit;
• persisting the configuration information from the first memory to the solid-state memory in the storage unit, by the storage unit, responsive to the requesting and the interlock disabling the read and write access by the processor to the first memory, with an energy reserve supporting the first memory and the solid-state memory;
• and
• utilizing the interlock to enable access by the processor to the first memory;
• and
• writing further configuration information to the first memory, responsive to the interlock re-enabling access by the processor to the first memory, with at least the persisting the configuration information is performed under continuous supplied power as a non-disruptive upgrade of the storage system.