Patent Application
20100115330
1. Technical Field
The present disclosure relates generally to the field of information handling systems, and more specifically, to managing redundant memory within information handling systems.
2. Background Information
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is an information handling system (IHS). An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for such systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
In an IHS, an uncorrectable or unrecoverable hardware error may adversely affect the operating system (OS) such as rendering it inoperative or unreponsive. For instance, internal chipset errors and corruption in the system memory may cause machine check exceptions or non-maskable interrupts (NMIs). In an IHS utilizing a Windows OS, NMIs may result in a bug check (e.g., BSOD or blue screen of death). In instances where IHSs employ virtualization, uncorrectable errors may create additional problems. For example, in a server environment implementing virtualization, a physical server may utilize virtualization software, such as a suitable OS, a hypervisor, a virtual machine monitor, a parent partition or any other program capable of virtualization. Virtualization software may enable several virtual machines (VMs), each simulating an IHS, to run on a single physical server or machine. Thus, if an uncorrectable error occurs in the server, it may cause all of the VMs running on the server to crash, thereby greatly reducing the benefits of VMs.
In order to prevent machine check exceptions or NMIs from occurring, some IHSs employ redundant memory techniques to enable recovery from uncorrectable memory errors. Such techniques may include but are not limited to spare memory row, memory mirroring, and memory redundant array of independent DIMMs (memory RAID). However, these forms of memory redundancy may require the mirroring of or redundancy for the entire system memory, thereby possibly significantly reducing the usable system memory. In some cases, current forms of memory redundancy may truncate the amount of usable system memory in half. Furthermore, since memory may prove to be an expensive component with a low failure-rate relative to other components in an IHS, currently employed memory redundancy techniques may not be considered cost-efficient.
Thus, a need exists for systems, methods, and media for providing redundant memory for a portion of system memory.
The following presents a general summary of several aspects of the disclosure in order to provide a basic understanding of at least some aspects of the disclosure. This summary is not an extensive overview of the disclosure. It is not intended to identify key or critical elements of the disclosure or to delineate the scope of the claims. The following summary merely presents some concepts of the disclosure in a general form as a prelude to the more detailed description that follows.
One aspect of the disclosure provides a method for managing a redundant memory architecture for an information handling system (IHS) may include providing redundant memory for a portion of system memory wherein the redundant memory is configured to mirror data stored in the portion of system memory. The method may further include reporting a parameter associated with the portion of system memory to an operating system of the IHS and executing a program from the portion of system memory.
Another aspect of the disclosure provides a method for managing a redundant memory architecture for an information handling system including selecting a portion of system memory for providing redundancy by mirroring the portion of system memory. The method further includes executing virtualization software from the portion of system memory, wherein the virtualization software is operable to create a virtual machine.
Another illustrative aspect of the disclosure provides an information handling system (IHS) including a system memory. The system further includes a memory controller configured to manage the system memory, wherein the memory controller is operable to selectively mirror a portion of the system memory. The system also includes an operating system stored within the system memory and in communication with the memory controller, wherein the operating system is operable to be selectively stored within the portion of system memory
Yet another aspect of the disclosure provides a computer-readable medium having computer-executable instructions for performing a method for providing a redundant memory architecture for an information handling system (IHS). The method may include providing redundant memory for a portion of system memory wherein the redundant memory is configured to mirror data stored in the portion of system memory. The method may further include reporting a parameter associated with the portion of system memory to an operating system of the IHS and executing a program from the portion of system memory.
For detailed understanding of the present disclosure, references should be made to the following detailed description of the several aspects, taken in conjunction with the accompanying drawings, in which like elements have been given like numerals and wherein:
Before the present systems, methods, and computer-readable mediums are described, it is to be understood that this disclosure is not limited to the particular apparatus, systems and methods described, as such may vary. One of ordinary skill in the art should understand that the terminology used herein is for the purpose of describing possible aspects, embodiments and/or implementations only, and is not intended to limit the scope of the present disclosure which will be limited only by the appended claims.
It must also be noted that as used herein and in the appended claims, the singular forms “a,” “and,” and “the” may include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a machine” refers to one or several machines, and reference to “a method of managing” includes reference to equivalent steps and methods known to those skilled in the art, and so forth.
For purposes of this disclosure, an embodiment of an Information Handling System (IHS) may include any instrumentality or aggregate of instrumentalities operable to compute, classify, process, transmit, receive, retrieve, originate, switch, store, display, manifest, detect, record, reproduce, handle, or utilize any form of information, intelligence, or data for business, scientific, control, or other purposes. For example, an IHS may be a personal computer, a storage device, or any other suitable device and may vary in size, shape, performance, functionality, and price. The IHS may include random access memory (RAM), one or more processing resources such as a central processing unit (CPU) or hardware or software control logic, ROM, and/or other types of nonvolatile memory. Additional components of the IHS may include one or more disk drives, one or more network ports for communicating with external devices as well as various input and output (I/O) devices, such as a keyboard, a mouse, and a video display. The IHS may also include one or more buses operable to transmit data communications between the various hardware components.
The memory controller 75 may manage the flow of data to memory as well as the flow of data out of memory. Additionally, the memory controller 75 may contain logic allowing it to read and write to dynamic random access memory (DRAM) as well as refresh the DRAM. Furthermore, the memory controller 75 may be capable of implementing memory redundancy including but not limited spare memory row, memory mirroring, memory RAID, and/or selective memory mirroring.
The IHS 5 may be implemented with a network port 45 to permit communication over a network 70 such as a local area network (LAN) or a wide area network (WAN), such as the Internet. As understood by those skilled in the art, IHS 5 implementations may also include an assortment of ports and interfaces for different peripherals and components, such as video display adapters 35, disk drives port 50, and input/output interfaces 40 (e.g., keyboard 60, mouse 65).
In an IHS, an uncorrectable or unrecoverable hardware error, such as an error in a memory subsystem, a system bus, or an I/O subsystem, may cause the IHS to crash. Moreover, in an IHS implementing virtualization, these errors may present additional difficulties. For example, virtualization software in an IHS may allow multiple software implemented machines, called virtual machines (VMs), to execute or run on a single, physical underlying machine. Under this framework, the virtualization software may manage and allocate the underlying machine's resources between all the VMs, though distinct sets of resources may be simulated for each individual VM. These resources may include, but are not limited to, processors, storage, and memory. Thus, since each VM may believe itself to exist as its own distinct IHS, this degree of separateness may enable different operating systems to be executed on each VM. Moreover, each VM may also implement its own subset of the virtualization software's instruction set architecture (ISA), which may differ from that of the underlying machine. Such flexibility may increase the efficiency and decrease the cost of the overall system. However, if an unrecoverable hardware error, such as a memory failure for example, were to occur and render the virtualization software inoperable or unresponsive, all the VMs running on the IHS would be rendered inoperable or unresponsive as well. Thus, rather than a single machine or process failing, multiple machines (VMs), each with possibly its own functionality and processes, may also fail, possibly creating a machine failure on a massive scale.
Therefore, some designers have implemented memory controllers configured to handle redundant memory techniques, such as spare memory row, memory mirroring, and memory redundant array of independent disks (memory RAID) to allow the IHS to recover from such errors. While these methods may alleviate concerns over the occurrences of unrecoverable errors, they may however, also require redundancy to be applied to the entire system memory. As a result, a system implementing such redundant memory architecture may require significantly more memory compared to that of a normal system to achieve the same amount of usable memory, thereby significantly increasing the cost of the system. Further, providing redundancy for the entire system memory may prove inefficient in instances where a user wishes to mirror only the data he/she deems critical.
Thus, in order to prevent multiple or all VMs in an IHS executing virtualization software from failing due to an uncorrectable error, while still maintaining a high degree of usable system memory, the present disclosure presents a system and method by which only a portion of the system memory may be selectively mirrored. To this end,
As depicted in
The virtualization software 208 may be loaded into and may execute in the mirrored portion of memory, which is represented by memory block 212a in MMC1206a and memory block 212b of MMC2206b. Thus, because the virtualization software resides in the portion memory for which there exists a mirrored copy, it may be protected against hardware failure, and in particular, memory failure. As a result, a hardware or memory failure may not cause a crash of all the VMs 220a-n supported by the virtualization software 208 as may be the result without the implementation of any memory redundancy. Indeed, because the virtualization software may possess the configuration data and variables concerning the VMs 220a-n, the VMs 220a-n may not need to be loaded into the mirrored portions (MMC1206a and MMC2206b) of system memory 204. To this end, as illustrated in
Though
Moreover, while not specifically illustrated in
Turning now to
Furthermore, methods of the present disclosure, detailed description and claims may be presented in terms of logic, software or software implemented aspects typically encoded on a variety of media or medium including, but not limited to, computer-readable medium/media, machine-readable medium/media, program storage medium/media or computer program product. Such media, having computer-executed instructions, may be handled, read, sensed and/or interpreted by an IHS. Generally, computer-executable instructions, such as program modules, may include routines, programs, objects, components, data structures, and the like, which perform particular tasks, carry out particular methods or implement particular abstract data types. Those skilled in the art will appreciate that such media may take various forms such as cards, tapes, magnetic disks (e.g., floppy disk or hard drive) and optical disks (e.g., compact disk read only memory (“CD-ROM”) or digital versatile disc (“DVD”)). It should be understood that the given implementations are illustrative only and shall not limit the present disclosure.
Although the present disclosure has been described with reference to particular examples, embodiments and/or implementations, those skilled in the art will recognize that modifications and variations may be made without departing from the spirit and scope of the claimed subject matter. Such changes in form and detail, including use of equivalent functional and/or structural substitutes for elements described herein, fall within the scope of the appended claims and are intended to be covered by this disclosure. In particular, the selective redundant memory technique envisioned in the present disclosure may also to apply to non-virtualized environments. Thus, while virtualization software and virtual machines may not exist in such environments, certain elements may still be designated to execute from within a selectively mirrored portion of system memory. For example, an operating system and/or other critical data or programs may be considered important applications and may be selected to run from the redundant portion of system memory.
