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Multiple action mechanism to force delay in removal of hot add options within an operating system

IP.com Disclosure Number: IPCOM000212159D
Publication Date: 2011-Nov-02
Document File: 5 page(s) / 66K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method to prevent damage to devices during removal from operational systems by guaranteeing the system enough time to properly disable onboard devices.

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This is the abbreviated version, containing approximately 51% of the total text.

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Multiple action mechanism to force delay in removal of hot add options within an operating system

The memory hot/replace feature in some systems allows customers to remove memory which has been flagged as potentially faulty (PFA), or increase memory capacity by adding memory, without shutting down the server. This particular feature relies on optical switches being mounted on a mechanical retention latch, which, if partially removed, signals that a user is attempting to remove the memory card. Once the signal fires indicating a hot removal, system software races in an attempt to quiesce the memory controller before removing/deactivating power for the specific memory card.

The end result is a very unreliable hot remove/add process, which frequently results in damaged memory cards or failed initialization of replaced memory due to the system applying power being improper times during the add sequence.

A more reliable method for the memory hot/replace procedure is needed. The method must have enough time built in from the beginning of removal to actual removal to allow the host system to properly remove power as well as turn off the appropriate buses to the cards/Dual In-Line Memory Modules (DIMMs) being removed/added.

Previous implementations relied on insertion/removal latches, which proved faulty as the lifting of the latches actually caused memory card(s) to remove from the memory card connector. This premature extraction typically resulted in system power faults, blown power fuses(s) on the memory card, and a failure to be initialized properly upon insertion due to incorrect power sequencing.

This invention prevents damage to devices during removal from operational systems by guaranteeing the system enough time to properly disable onboard devices.

Using this invention, a simple circuit through one part of the mechanism signals the intention to remove the card/device when moved. Upo...