Showing papers on "Data Corruption published in 2007"

Mitigation of data corruption from back pattern and program disturb in a non-volatile memory device

Abstract: In one of the disclosed embodiments, a write algorithm is used to remove errors due to back pattern effects, cell-to-cell capacitive coupling, and program disturb in memory cells. Original data to be programmed is adjusted prior to an initial programming operation of the memory cells. The original data is then programmed into the memory cells in another programming operation. In an alternate embodiment, a read adjustment weight data value is associated with each series string of memory cells. The weight data value is used to compensate data read during an initial word line read. The weight data value is updated after each read and read adjustment such that the adjusted weight data value is used on the subsequent read operations.

Method and system for handling reallocated blocks in a file system

Abstract: A system for managing a file system. In response to a user selecting an image of the file system to perform a rollback operation, each data block in the file system that is owned by the image is searched for. Then, it is determined whether a data block owned by the image is marked in a first map and a second map. In response to determining that the data block owned by the image is marked in the first map and the second map, the data block is marked in a third map. In response to determining that the data block owned by the image is marked in the third map, a new data block is allocated in the file system. Subsequently, data from the data block owned by the image is copied to the new data block in the file system prior to performing the rollback operation to avoid a collision that causes data corruption.

Apparatus, system, and method for hierarchical rollback of business operations

Abstract: An apparatus, system, computer program product and method are disclosed for the hierarchical rollback of business objects on a datastore. The hierarchical rollback method utilizes a non-linear process designed to restore data to a previous point in the case of a data modification failure in order to prevent incorrect linking and data corruption. The hierarchical rollback methods are generated by retrieving existing data and creating commands in an order that will prevent orphan data in a datastore.

Protection of point-in-time application data using snapshot copies of a logical volume

Abstract: Providing protection of point-in-time application data includes obtaining a plurality of original snapshot copies of an original logical volume containing the application data, causing the original snapshot copies to be tested for data corruption, and restoring data corresponding to one of the original snapshot copies. Application data is accessible by an application prior to completion of the restoration. One of the original snapshot copies may be restored to the original logical volume and/or to a new logical volume different from the original logical volume. Prior to completion of the restoration, particular data may be restored to the original logical volume or to the new logical volume prior to an operation to access the particular data. The original snapshot copies may be provided as virtual devices.

Apparatus for detecting and recovering data corruption in reading in non-access memory cell, and method thereof

Abstract: PROBLEM TO BE SOLVED: To provide an effective inspection method in order to solve the problem that read disturbance in a flash memory may cause corruption of data not to be read and uncorrectable data corruption may be caused before an inspection. SOLUTION: A non-volatile data storage apparatus comprises a plurality of memory cells and a memory controller. The memory controller counts how many times memory cells are read in each control area. When the counted number of times for a first control area exceeds a first threshold value, the memory controller reads data and an error correction code which are stored in the memory cell in the first control area, and decrypts the read error correction code. When the number of errors contained in the read data exceeds a second threshold value, data corrected by decrypting the error correction code is written to the control area other than the first control area. COPYRIGHT: (C)2009,JPO&INPIT

Database Isolation and Filtering against Data Corruption Attacks

Abstract: Various attacks (e.g., SQL injections) may corrupt data items in the database systems, which decreases the integrity level of the database. Intrusion detections systems are becoming more and more sophisticated to detect such attacks. However, more advanced detection techniques require more complicated analyses, e.g, sequential analysis, which incurs detection latency. If we have an intrusion detection system as a filter for all system inputs, we introduce a uniform processing latency to all transactions of the database system. In this paper, we propose to use a "unsafe zone" to isolate user's SQL queries from a "safe zone" of the database. In the unsafe zone, we use polyinstantiations and flags for the records to provide an immediate but different view from that of the safe zone to the user. Such isolation has negligible processing latency from the user's view, while it can significantly improve the integrity level of the whole database system and reduce the recovery costs. Our techniques provide different integrity levels within different zones. Both our analytical and experimental results confirm the effectiveness of our isolation techniques against data corruption attacks to the databases. Our techniques can be applied to database systems to provide multizone isolations with different levels of QoS.

Data refresh device, and data refresh method

Abstract: PROBLEM TO BE SOLVED: To provide a data refresh device and a data refresh method which allow data to be protected in accordance with a write frequency and a degree of data corruption. SOLUTION: The data refresh device refreshes data stored in a storage device comprising a plurality of storage areas and includes an error detection means for detecting the number of errors occurring in data stored in the storage areas, an error correction means for correcting errors of data stored in the storage areas, a refresh means for writing corrected data corrected by the error correction means to one of the storage areas, and a refresh control means for controlling the operation cycle of the refresh means in accordance with the frequency of write to the storage areas. COPYRIGHT: (C)2009,JPO&INPIT

AScalable,Timing-Safe,Network-on-ChipArchitecturewithanIntegrated ClockDistributionMethod

Abstract: Growing system sizes together with increasing performance variability are making globally synchronous operation hard to realize. Mesochronous clocking constitutes a possible solution to the problems faced. The most fundamentalofproblemsfacedwhencommunicatingbetween mesochronously clocked regions concerns the possibility of data corruption caused by metastability. This paper presents an integrated communication and mesochronous clockingstrategy,whichavoidstimingrelatederrorswhile maintaining a globally synchronous system perspective. The architecture is scalable as timing integrity is based purely on local observations. It is demonstrated with a 90 nm CMOS standard cell network-on-chipdesign which implements completely timing-safe, global communication inamodularsystem.

Methodology to enhance the predictability of i/o data exchange between device and tasks

Abstract: Data coming from devices shall be transported to a specific task to be used in a software with the most accurate time and data integrity. During this process, a potential cause for invoking structured hazard and performance degradation is dormant. In this paper, a method which can protect the data integrity from the possible data corruption when collision has happened during I/O data exchange between device and tasks is presented. Also, an example diagram of mechanism according to the method is shown and the effect, merits and demerits of the method is evaluated.