Patent Publication Number: US-2010131696-A1

Title: System and Method for Information Handling System Data Redundancy

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates in general to the field of information handling system data storage, and more particularly to a system and method for information handling system data redundancy. 
     2. Description of the Related Art 
     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 information handling systems. 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 information handling 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. 
     Information handling systems create and store data that often has a great deal of importance to businesses and individuals. Businesses often secure data from inadvertent or even intentional loss by maintaining back-up copies. For example, small businesses typically run tape drives periodically, such as at the end of each business day, so that a separate copy of data is maintained. Larger businesses often employ more advanced data redundancy schemes, such as maintaining mirror images of data at distal locations so that a disruption of on-site storage devices will allow a back-up from off-site storage devices. Individuals have traditionally maintained back-ups with local storage devices, such as tape drives or external hard disk drives, but have more recently been offered opportunities to back-up data with off site storage devices accessed through the Internet. 
     Periodic back-ups help to preserve data should a primary storage device fail, however, a periodic back-up does not preserve data created during the time period between back-ups. While the amount of data created between back-ups may be insubstantial in size relative to all of the backed-up data, the most-recently created data usually has greater relevance to a business or individual who uses the data. Performing data back-ups with greater frequency and the passage of less time between back-ups tends to reduce the impact of data loss, however, frequent data back-ups can interfere with the normal operations, thus annoying end users. One alternative is to integrate mirroring of stored data within an information handling system or storage system by incorporating multiple hard disk drives, such as with a RAID configuration. In the event of a failure of one hard disk drive, the data remains available from the mirrored hard disk drive. Although RAID configurations provide redundancy, the installation of the extra hard disk drive increases the cost of the system and the size of the system. Because RAID configurations require power and room for multiple hard disk drives, they are not normally used in portable information handling systems which are built to minimize power consumption and size. Regular data back-ups with portable information handling systems present a challenge since portable systems may not interface with stationary back-up storage devices at regular intervals. 
     SUMMARY OF THE INVENTION 
     Therefore a need has arisen for a system and method which backs-up data at an information handling system without substantially increasing the size or power consumption of the information handling system. 
     In accordance with the present invention, a system and method are provided which substantially reduce the disadvantages and problems associated with previous methods and systems for backing up data at an information handling system. Non-volatile memory, such as flash memory, integrated in a hard disk drive chassis maintains intermediate back-up data for changes made to the hard disk drive between incremental back-ups. 
     More specifically, an information handling system has plural components built into a housing, such as a CPU, RAM, a hard disk drive, a chipset, a NIC and a display. The hard disk drive is backed-up at a storage device external to the information handling system, such as through a network. A redundancy module maintains back-up data in a flash memory that is integrated in the hard disk drive so that intermediate back-up data remains available for incremental back-up of the hard disk drive at the external storage device. The redundancy module monitors the capacity available in the flash memory and issues a notice that a back-up is needed if the flash memory available storage capacity is less than a predetermined threshold. If the data on the hard disk drive is successfully backed-up, the back-up data on the flash memory is erased so that the flash memory is reset to track new changes to the data on the hard disk drive. If the hard disk drive fails, the back-up data on the flash memory is retrieved so that a complete back-up of the hard disk drive remains available, including intermediate data changes made after an incremental back-up. 
     The present invention provides a number of important technical advantages. One example of an important technical advantage is that data is backed up at an information handling system without substantially increasing the size or power consumption of the information handling system. The relatively small amounts of flash memory used to maintain a concurrent back-up fits within the housing of a hard disk drive and shares the hard disk drive controller and power subsystem so that the impact of concurrent storage on system size and cost are minimal. The size of flash memory used for the concurrent back-up of information stored on the hard disk drive is minimized by reminding the end user to back-up the data at an external storage location at regular intervals and when the flash becomes full. Further, flash memory is likely to successfully store data under conditions where a hard disk drive might fail, such as when a portable information handling system is dropped causing damage to the rotating magnetic disk of the hard disk drive. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention may be better understood, and its numerous objects, features and advantages made apparent to those skilled in the art by referencing the accompanying drawings. The use of the same reference number throughout the several figures designates a like or similar element. 
         FIG. 1  depicts a block diagram of an information handling system having a hard disk drive having integrated flash memory that maintains a back-up of new information stored on the hard disk drive; and 
         FIG. 2  depicts a flow diagram of a process for maintaining a back-up of data stored on a hard disk drive in a flash memory associated with the hard disk drive. 
     
    
    
     DETAILED DESCRIPTION 
     Flash memory integrated in a hard disk drive chassis maintains a back-up of data changes to the hard disk drive between back-ups of the hard disk drive to a separate storage device or information handling system. For purposes of this disclosure, an information handling system 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 information handling system may be a personal computer, a network storage device, or any other suitable device and may vary in size, shape, performance, functionality, and price. The information handling system 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 information handling system 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 information handling system may also include one or more buses operable to transmit communications between the various hardware components. 
     Referring now to  FIG. 1 , a block diagram depicts an information handling system  10  having a hard disk drive  12 , the hard disk drive having integrated flash memory  14  that maintains a back-up of new information stored on the hard disk drive. Information handling system  10  is built in a housing  16  that supports a variety of components that cooperate to process information. A CPU  18  processes information using RAM  20  to provide temporary storage of information and a chipset  22  that has firmware instructions, such as a BIOS, to coordinate the interaction of hardware components. A network interface card (NIC)  24  supports network communications between information handling system  10  and a network  26 , such as a local area network (LAN), a storage area network (SAN) or the Internet. Hard disk drive  12  provides permanent storage of information on a magnetic disk  28  which spins relative to a head  30 . A controller  32  manages reads from disk  28  and writes to disc  28  by controlling head  30 . Hard disk drive  12  is built into a chassis  34 , which fits into information handling system housing  16 . A display monitor  36  built into information handling system housing  16  supports the presentation of information in a portable system. Although  FIG. 1  depicts integrated flash memory  14  to store information, other types of non-volatile memory could be used. 
     In operation, applications running on CPU  18  generate data for storage on hard disk drive  12 . For example, an application running over an operating system on CPU  18  reads data from hard disk drive  12  and writes data to hard disk drive  12  through a driver of the operating system. As the data on hard disk drive  12  changes, a redundancy module  38  running in firmware of chipset  22  mirrors the changes as back-up data  40  stored in flash memory  14 . Redundancy module  38  maintains back-up data  40  that reflects changes made to data stored on magnetic disk  28  since at least the most recent back-up of the data to a back-up storage  42 . When information handling system  10  interfaces with back-up storage  42 , a back-up is initiated either automatically on in response to an end user input. The back-up of hard disk drive is provided either directly from hard disk drive  12  or from back-up data  40  in flash memory  14 . Once a back-up of hard disk  12  is completed at back-up storage  42 , redundancy module  38  erases back-up data  40  and resets flash memory  14  to begin a new back-up of data changes made to hard disk drive  12 . Although  FIG. 1  depicts redundancy module  38  as running in firmware of chipset  22 , in alternative embodiments redundancy module runs as firmware in hard disk drive  12 , such as on controller  32 , as a driver of an operating system running on CPU  18 , such as Windows, or as a number of distributed modules that run on CPU  18 , chipset  22  and hard disk drive  12 . 
     During normal operations, redundancy module  38  maintains back-up data  40  as a mirror of changes made to data stored on hard disk drive magnetic disk  28  since the most recent back-up of hard disk drive  12 . If available storage on flash memory  14  crosses a threshold value, redundancy module  38  initiates presentation of a notice at display  36  that a back-up is required. If hard disk drive  12  fails, then redundancy module  38  retrieves back-up data  40  to update back-up storage  42  so that a complete copy of the information stored on magnetic disk  28  is available in back-up storage  42 . Even in the event of magnetic media failure, redundancy module  38  is still available to retrieve back-up data  40  to storage  42 . Erasing back-up data  40  and resetting flash memory  14  at each back-up to back-up storage  42  minimizes the amount of flash memory  14  needed to maintain a current back-up of hard disk drive  12 . Integration of flash memory into hard disk drive chassis  34  allows intermediate back-ups into flash memory  14  between back-ups of hard disk drive  12  with the controller and power subsystem of hard disk drive  12 . Further, integration of flash memory  14  into hard disk drive chassis  34  ensures that the intermediate back-up data associated with hard disk drive  12  remains physically with hard disk drive  12 . 
     Referring now to  FIG. 2 , a flow diagram depicts a process for maintaining a back-up of data stored on a hard disk drive in a flash memory associated with the hard disk drive. The process starts at step  42 , such as at power-up to the hard disk drive, and proceeds to step  44  for a change to the data stored on an information handling system hard disk drive  44 , such as a write of new data. At step  46 , the data is written to the hard disk drive magnetic disk, and at step  48  the data is redundantly written to a partition on flash memory, such as flash memory integrated into the chassis of the hard disk drive. At step  50 , a determination is made of whether the flash memory storage capacity has reached a predetermined threshold. If the threshold has been reached indicating that the flash memory is approaching full capacity, the process continues to step  52  to notify the host information handling system that an incremental back-up is required due to the limited remaining back-up capacity. If the threshold is not reached, the process continues to step  54  to continue normal operations. 
     At step  56  a determination is made of whether the host information handling system is interfaced with a back-up storage device, such as an external storage device. If not, the process returns to step  42 . If an external back-up storage device is available, the process continues to step  58  to update the back-up of the hard disk drive with new data from the hard disk drive or from the flash memory partition. After performing the back-up, the process continues to step  60  to notify the hard disk drive that the redundant data partition in the flash memory can be reset. At step  62 , the partition for the data back-up is reset and the process returns to step  42 . The dotted line around steps  46  to  54  and step  62  indicate the functions performed by hard disk drive firmware in one example embodiment. 
     Although the present invention has been described in detail, it should be understood that various changes, substitutions and alterations can be made hereto without departing from the spirit and scope of the invention as defined by the appended claims.