Abstract: Techniques are provided to enable non-disruptive upgrades of multipath device drivers. A multipath device driver includes a core module and a thin module. The core module is configured to implement all multipathing functionality of the multipath device driver, and the thin module is configured to create and maintain an instance of a multipath device, which is utilized by the core module to control I/O operations over a plurality of I/O paths from the host system to an array of data storage devices. In response to an upgrade command, the thin module replaces I/O entry points of the core module so that I/O operation requests are routed to the thin module during an upgrade operation of the core module. The thin module utilizes the instance of the multipath device during the upgrade operation to execute the I/O operation requests that are routed to the thin module.

Abstract: Example embodiments of the present invention relate to a method, an apparatus, and a computer program product for updating disk geometry in a multipathing environment. The method includes receiving a disk geometry update for a logical unit on a storage array accessible via a multipathing device in the multipathing environment. The method then includes translating the disk geometry update for the logical unit for each respective disk device aggregated by the multipathing device. Requests for the logical unit then may be issued according to the updated geometry.