Patent application number | Description | Published |
20090055584 | DETECTION AND CORRECTION OF DROPPED WRITE ERRORS IN A DATA STORAGE SYSTEM - Method, system and computer program product are provided for detecting and correcting dropped writes in a storage system. Data and a checksum are written to a storage device, such as a RAID array. The state of the data is classified as being in a “new data, unconfirmed” state. The state of written data is periodically checked, such as with a timer. If the data is in the “new data, unconfirmed” state, it is checked for a dropped write. If a dropped write has occurred, the state of the data is changed to a “single dropped write confirmed” state and the dropped write error is preferably corrected. If no dropped write is detected, the state is changed to a “confirmed good” state. If the data was updated through a read-modified-write prior to being checked for a dropped write event, its state is changed to an “unquantifiable” state. | 02-26-2009 |
20090055688 | DETECTION AND CORRECTION OF DROPPED WRITE ERRORS IN A DATA STORAGE SYSTEM - Methods are provided for detecting and correcting dropped writes in a storage system. Data and a checksum are written to a storage device, such as a RAID array. The state of the data is classified as being in a “new data, unconfirmed” state. The state of written data is periodically checked, such as with a timer. If the data is in the “new data, unconfirmed” state, it is checked for a dropped write. If a dropped write has occurred, the state of the data is changed to a “single dropped write confirmed” state and the dropped write error is preferably corrected. If no dropped write is detected, the state is, changed to a “confirmed good” state. If the data was updated through a read-modified-write prior to being checked for a dropped write event, its state is changed to an “unquantifiable” state. | 02-26-2009 |
20100251072 | DETECTION AND CORRECTION OF DROPPED WRITE ERRORS IN A DATA STORAGE SYSTEM - A RAID system is provided for detecting and correcting dropped writes in a storage system. Data and a checksum are written to a storage device, such as a RAID array. The state of the data is classified as being in a “new data, unconfirmed” state. The state of written data is periodically checked, such as with a timer. If the data is in the “new data, unconfirmed” state, it is checked for a dropped write. If a dropped write has occurred, the state of the data is changed to a “single dropped write confirmed” state and the dropped write error is preferably corrected. If no dropped write is detected, the state is changed to a “confirmed good” state. If the data was updated through a read-modified-write prior to being checked for a dropped write event, its state is changed to an “unquantifiable” state. | 09-30-2010 |
Patent application number | Description | Published |
20080256420 | ERROR CHECKING ADDRESSABLE BLOCKS IN STORAGE - Provided are a method, system, and article of manufacture for error checking addressable blocks in storage. Addressable blocks of data are stored in a storage in stripes, wherein each stripe includes a plurality of data blocks for one of the addressable blocks and at least one checksum block including checksum data derived from the data blocks for the addressable block. A write request is received to modify data in one of the addressable blocks. The write and updating the checksum are performed in the stripe having the modified addressable block. An indication is made to perform an error checking operation on the stripe for the modified addressable block in response to the write request, wherein the error checking operation reads the data blocks and the checksum in the stripe to determine if the checksum data is accurate. An error handling operation is initiated in response to determining that the checksum data is not accurate. | 10-16-2008 |
20090172468 | METHOD FOR PROVIDING DEFERRED MAINTENANCE ON STORAGE SUBSYSTEMS - A set of disks in a plurality of disk arrays are configured to have one or more spare partitions. Upon detecting a faulty disk in a faulty array, the method involves the steps of: (a) migrating data in the faulty array containing the faulty disk to one or more spare partitions; (b) reconfiguring the faulty array to form a new array without the faulty disk; (c) migrating data from one or more spare partitions in the set of disks to the reconfigured new array; (d) monitoring to identify when overall spare capacity falls below a predetermined threshold; and when the predetermined threshold is exceeded, scheduling a service visit for replacement of the failed disks. | 07-02-2009 |
20090313499 | SYSTEM AND METHOD FOR RECONSTRUCTING LOST DATA IN A STORAGE SYSTEM - A system (and method) for determining reconstruction formulas for partial strip reconstruction in a storage system in which a plurality of lost strips have been detected, includes using a combination of a direct reconstruction method and a sequential reconstruction method. | 12-17-2009 |
20130054873 | STORAGE SYSTEM CACHE USING FLASH MEMORY WITH DIRECT BLOCK ACCESS - Embodiments of the invention enable a storage cache, comprising flash memory devices, to have direct block access to the flash such that the physical block addresses are presented to the storage system's cache layer, which thereby controls the storage cache data stream. An aspect of the invention includes a caching storage system. The caching storage system comprises a plurality of flash memory units organized in an array configuration. Each of the plurality of flash memory units includes at least one flash memory device and a flash unit controller. Each flash unit controller provides the caching storage system with direct physical block access to its corresponding at least one flash memory device. The caching storage system further comprises a storage cache controller. The storage cache controller selects physical block address locations (within a flash memory device) to be erased where data are to be written, issues erase commands to a flash unit controller corresponding to the selected physical block address locations, and issues page write operations to a set of erase blocks. | 02-28-2013 |