Disk array enclosure (dae) firmware-based systems and methods for firmware upgrades

A system comprising:

• a processor;
• and memory configured to store one or more sequences of instructions which, when executed by the processor, cause the processor to carry out the steps of:
• receiving a request to upgrade firmware for a plurality of disk array enclosures (DAEs) in a storage system, wherein each DAE is reachable by a host server using first and second paths,
• wherein the first path extends from a first port of a first host bus adapter (HBA) of the host server to each of a plurality of first input/output modules (IOMs) in the DAEs, the plurality of first IOMs having first serial attached SCSI (SAS) expanders to which a plurality of storage disks are connected;
• setting a flag in firmware of each IOM of the plurality of first IOMs in each DAE that causes SAS management protocol (SMP) and SCSI enclosure services (SES) protocol services of a DAE to mark each respective storage disk connected to each respective SAS expander of the plurality of first SAS expanders as vacant;
• upgrading the firmware of the plurality of first IOMs, the upgrading thereby causing each SAS expander of the first SAS expanders and each storage disk of the plurality of storage disks to be reset and corresponding topology change events to be generated;
• and
• during the upgrading and based on the flag that has been set, withholding advertising to a SAS driver in the host server of topology change events indicating that a storage disk of the plurality of storage disks has been added or removed.

A computer program product, comprising a non-transitory computer-readable medium having a computer-readable program code embodied therein, the computer-readable program code adapted to be executed by one or more processors to implement a method comprising:

• receiving a request to upgrade firmware for a plurality of disk array enclosures (DAEs) in a storage system, wherein each DAE is reachable by a host server using first and second paths,
• wherein the first path extends from a first port of a first host bus adapter (HBA) of the host server to each of a plurality of first input/output modules (IOMs) in the DAEs, the plurality of first IOMs having first serial attached SCSI (SAS) expanders to which a plurality of storage disks are connected;
• setting a flag in firmware of each IOM of the plurality of first IOMs in each DAE that causes SAS management protocol (SMP) and SCSI enclosure services (SES) protocol services of a DAE to mark each respective storage disk connected to each respective SAS expander of the plurality of first SAS expanders as vacant;
• upgrading the firmware of the plurality of first IOMs, the upgrading thereby causing each SAS expander of the first SAS expanders and each storage disk of the plurality of storage disks to be reset and corresponding topology change events to be generated;
• and
• during the upgrading and based on the flag that has been set, withholding advertising to a SAS driver in the host server of topology change events indicating that a storage disk of the plurality of storage disks has been added or removed.