[n: On Discs] [n9607] {g11b 20/12d} Patents (Class G9B/20.027)
  • Publication number: 20130064052
    Abstract: Upon receiving a request to allocate a storage region, a storage device may initialize the contents of the storage device to default values (e.g., zero) in order to avoid problems arising from unknown data stored in the locations of the storage region (e.g., upon writing a data set to a location involved in a mirroring relationship, uninitialized data in the corresponding mirror location may result in a mismatch that jeopardizes the written data). However, initializing the storage device may be time-consuming and inefficient. Instead, a usage bitmap may be generated that, for respective location sets of the storage region, indicates whether values exist in the location. A read request may be fulfilled by examining the usage bitmap to determine whether values exist in the specified location, and if not, the default value may be returned without accessing the storage device. Other efficiencies may also be achieved using the usage bitmap.
    Type: Application
    Filed: September 12, 2011
    Publication date: March 14, 2013
    Applicant: Microsoft Corporation
    Inventors: Karan Mehra, Surendra Verma, John R. Dietrick
  • Publication number: 20110182162
    Abstract: An apparatus includes a recorder having at least two optical pickup heads for simultaneously recording at least two bit streams on respective layers of recordable media in one of an opposite track path and a parallel track path.
    Type: Application
    Filed: January 12, 2007
    Publication date: July 28, 2011
    Inventor: Alan Bruce Hamersley
  • Publication number: 20090147644
    Abstract: An information recording apparatus and method can prevent an information recording medium having a plurality of recording layers from being incompatible with a reproduction-only information recording medium due to an unrecorded area, which is produced by completion of recording in a middle of a data area of the recording layer. The recording layers include at least a first recording layer and a second recording layer, the first recording layer providing a reference with respect to a position of said data area in each of the recording layers. The user data is recorded in response to a recording request. After recording the user data, predetermined data is recorded in a predetermined unrecorded area in the second recording layer.
    Type: Application
    Filed: February 10, 2009
    Publication date: June 11, 2009
    Inventor: Yoshiyuki Sasaki