Browse Prior Art Database

Firmware Assisted Dump in a Partitioned Environment using Reserved Partition Memory

IP.com Disclosure Number: IPCOM000166859D
Original Publication Date: 2008-Jan-25
Included in the Prior Art Database: 2008-Jan-25
Document File: 2 page(s) / 28K

Publishing Venue

IBM

Abstract

Disclosed is a method for firmware assisting a partition during a memory dump using reserved partition memory

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Firmware Assisted Dump in a Partitioned Environment using Reserved Partition Memory

The specific problem solved by this disclosure is related to processing of a partition Operating System (OS) memory dump. When an OS detects an internal problem severe enough to require a reboot an attempt is made to save critical information such as memory and registers to an IO device (Tape, Dasd, CD, etc....) to help determine the cause of the problem at a later date.

    Currently this is done by the OS at the time the error is detected. The major flaw with this approach is that OS has already detected a severe internal error and that error may affect the OS's ability to capture a valid dump. Ideally the OS should be restarted to perform the dump but reboot process is destructive to some of the partition's data making it impossible to capture a useful dump.

    One solution to this problem is to have firmware do some of the dump. The drawback to this solution is that now the firmware has to have knowledge of the OS and underlying hardware. Anytime a new OS type is supported or new hardware is introduced firmware has to be modified.

    A solution that allows the OS to restart without the firmware having knowledge of either the OS or the hardware is needed.

    This invention allows the OS complete the dump on reboot without data loss, without the firmware knowledge of the OS and its hardware, and minimizes the amount of memory reserved by the OS for a dump mode boot.

    When the OS detects the need for a dump, instead of processing the data in error mode a dump reboot is requested. When the firmware receives this request the data that is overwritten by a partition reboot is copied to a reserved area in the partition's memory. The partition is then booted in dump mode and writes the dump data to an IO device. When an area that has been modified due to the reboot is encountered the data is written from the save area instead. To reduce the size of the partition's reserved dump save area the OS should recognize the dump boot and initialize a minimal dump version of the OS to limit the memory requirements until the critical data has been saved.

    By copying the data to the partition's memory and allow...