Abstract: The error tolerance of an array of m storage units is increased by using a technique referred to as “dodging.” A plurality of k stripes are stored across the array of storage units in which each stripe has n+r elements that correspond to a symmetric code having a minimum Hamming distance d=r+1. Each respective element of a stripe is stored on a different storage unit. An element is selected when a difference between a minimum distance of the donor stripe and a minimum distance of a recipient stripe is greater or equal to 2. The selected element is also stored on a storage unit having no elements of the recipient stripe. A lost element of the recipient stripe is then rebuilt on the selected element.
Type:
Grant
Filed:
July 14, 2003
Date of Patent:
May 12, 2009
Assignee:
International Business Machines Corporation
Inventors:
Steven Robert Hetzler, Daniel Felix Smith
Abstract: Network latencies are reduced by detecting a metadata access call for filesystem metadata contained in a filesystem node of remotely located filesystem. The metadata corresponding to the metadata access call is fetched when the metadata corresponding to the metadata access call is not contained in a local filesystem cache that has a hierarchical structure corresponding to a hierarchical structure of the remotely located filesystem. Metadata related to the metadata corresponding to the metadata access call from the remotely located filesystem is prefetched when the related metadata is not contained in the local filesystem cache. The metadata related to the metadata corresponding to the access call can be contained in a child node or a parent node of the node containing the metadata corresponding to the access call, or the descendants of such nodes.
Type:
Grant
Filed:
September 29, 2004
Date of Patent:
February 24, 2009
Assignee:
International Business Machines Corporation
Abstract: When an alarm condition relating to a performance goal of a storage system is detected, a storage management system invokes an N-step lookahead engine for simulating operation of the storage system when there are multiple actions that could be taken by the storage system for eliminating the alarm condition. The N-step lookahead engine generates N possible system states based on a current state of the storage system. The N possible states are based on a cost model of each of the multiple actions. Each cost model is based on an action, a behavior implication of the action, a resource implication of the action and a transient cost of the action. An action is selected that generates a system state that optimizes the stability, a prerequisite and a transient cost of invoking the selected action.
Type:
Grant
Filed:
September 30, 2004
Date of Patent:
February 17, 2009
Assignee:
International Business Machines Corporation
Inventors:
John Davis Palmer, Sandeep Madhav Uttamchandani, Kaladhar Voruganti
Abstract: A soft play pillow having a secret hiding place cavity concealed by a door. An item such as a small stuffed animal or toy is hidden in the secret hiding place to intrigue children and entice them to play a quiet game of game of peek-a-boo with the pillow and the item inside. The soft pillow preferably has indicia which together with the item visually indicate an illustrated theme, such as, an animal barn or building theme, frog and lily pad theme, horse theme, religious theme, vehicular theme or bear theme. The soft pillow may include additional cavities and additional doors, and may further include places to hold books and pictures.
Type:
Grant
Filed:
September 12, 2003
Date of Patent:
December 9, 2008
Inventors:
Julia Sarah Faircloth, Nellie Tara Faircloth
Abstract: Magnetic medium recording performance can be enhanced by irradiating a magnetic medium with ions having an acceleration voltage of between 10 keV and 100 keV to induce exchange coupling between grains of the magnetic medium. The magnetic medium is exposed to a cumulative ion dosage of between 1013 ions/cm2 and 1017 ions/cm2 using a non-patterned exposure of the magnetic medium. The ions can be selected from the group consisting of H+, He+, Ne+, Ar+, Kr+, and Xe+. Alternatively, the ions can be selected from the group consisting of Ga+, Hg+, and In+.
Type:
Grant
Filed:
January 29, 2004
Date of Patent:
September 16, 2008
Assignee:
International Business Machines Corporation
Inventors:
Manfred Albrecht, Charles Thomas Rettner, Bruce David Terris, Thomas Thomson
Abstract: A container that can hold a liquid, such as paint, or a granulated material includes a side wall portion, a bottom portion formed at one end of the side wall portion, and a well region formed in the bottom portion. The bottom portion includes an inclined surface. Alternatively, the bottom portion can be shaped to be frustoconical, hemispherical or an inverted pyramid.
Abstract: A spring arrangement for a trampoline includes a rebounding surface, a frame structure having a top portion and a bottom portion, and a plurality of spring members that are mechanically coupled between the rebounding surface and the frame structure. A first group of spring members are mechanically coupled to the top portion of the frame structure and a second group of spring members are mechanically coupled to the bottom portion of the frame structure. In one exemplary embodiment, the spring members of the first group and the second group are alternately arranged along the frame structure. In another exemplary embodiment, the frame structure is formed by a plurality of frame members.
Abstract: An optimum pathway to data stored on a data storage system having N storage devices and more than N pathways is determined in response to a read request for the data. A sorter separates the read request into an appropriate segment size for sending to the storage devices of the data storage system. An assigner generates the set of read permutations satisfying the read request. A read permutation is selected based on a metric. A collector receives the requested data from the N storage devices in response to the selected read permutation being sent to the storage devices.
Type:
Grant
Filed:
July 14, 2003
Date of Patent:
May 27, 2008
Assignee:
International Business Machines Corporation
Inventors:
Steven Robert Hetzler, Daniel Felix Smith
Abstract: Desired transformations such as compression, encryption and/or encoding are applied to data such that the number of duplicate chunks in the transformed data is increased and the chunks are predominantly of a predetermined size. Additionally, the unique and duplicate chunks of transformed data are identified. A variable-sized window is passed over the set of data to generate a working chunk of transformed data that is of the predetermined size. When the working chunk is a duplicate chunk of data, a next group of untransformed data is selected from the set of data, transformed and then evaluated. When the working chunk is not a duplicate chunk of data, a next group of data is selected by sliding the window over the set of data to generate another working chunk that is evaluated.
Type:
Grant
Filed:
June 30, 2004
Date of Patent:
November 6, 2007
Assignee:
International Business Machines Corporation
Abstract: Error tolerance is increased for a storage system having a plurality of arrays by making local redundancy in a selected array globally available throughout the storage system. To achieve the increased error tolerance, a donor array is selected from the plurality of arrays when the difference between a minimum Hamming distance of the donor array and a minimum Hamming distance of a recipient array is greater or equal to 2. A donor storage unit is selected in the donor array and recipient information is then rebuilt from the recipient array on the selected storage unit. The selected storage unit is indicated to the donor array as having been donated before the lost information is rebuilt on the selected storage unit. Preferably, the minimum Hamming distance of the recipient array is d?2 before the donor array is selected from the plurality of arrays.
Type:
Grant
Filed:
July 14, 2003
Date of Patent:
October 9, 2007
Assignee:
International Business Machines Corporation
Inventors:
Steven Robert Hetzler, Daniel Felix Smith
Abstract: A magnetic tunnel element that can be used, for example, as part of a read head or a magnetic memory cell, includes a first layer formed from an amorphous material, an amorphous tunnel barrier layer, and an interface layer between the first layer and the tunnel barrier layer. The interface layer is formed from a material that is crystalline when the material is in isolation from both the first layer and the tunnel barrier layer. Alternatively, the thickness of the interface layer is selected so that the interface layer is not crystalline. The first layer is formed from at least one material selected from the group consisting of amorphous ferromagnetic material, amorphous ferromagnetic materials, and amorphous non-magnetic materials. The interface layer is formed from a material selected from the group consisting of a ferromagnetic material and a ferrimagnetic material.
Type:
Grant
Filed:
June 13, 2005
Date of Patent:
October 2, 2007
Assignee:
International Business Machines Corporation
Inventors:
Stuart Stephen Papworth Parkin, Mahesh Govind Samant