Emc Corporation

Emc IP Holding Company LLC

Pei-Ching Hwang

Arieh Don

Michael J Scharland

Rong Yu

Dan Aharoni

Stephen Richard Ives

Yechiel Yochai

Peng Yin

Orit Levin-Michael

Qun Fan

John W Lefferts

Anestis Panidis

Michael E Specht

Kenneth A Halligan

Jeffrey A Lewis

Andrew Ralich

Described are techniques for processing a data operation in a data storage system. A front-end component of the data storage system receives the data operation. In response to receiving the data operation, the front-end component performs first processing. The first processing includes determining whether the data operation is a read operation requesting to read a data portion which results in a cache miss; and if said determining determines that the data operation is a read operation resulting in a cache miss, performing read miss processing. Read miss processing includes sequential stream recognition processing performed by the front-end component to determine whether the data portion is included in a sequential stream.

Techniques for data prefetching

Described are techniques for migrating data from a source device to a target device. A source device descriptor of the source device including source device geometry parameters and a source device partition definition structure is received. Target device geometry parameters are received. The source partition definition structure is translated and a mapped partition definition structure in accordance with the target device geometry parameters is generated. A target device descriptor including the target device geometry parameters and the mapped partition definition structure is generated. The target device descriptor is stored on the target device. Data for one or more partitions of the source device is migrated to the target device.

Geometry adaptation using data redistribution

Described is a technique for initialization of a device in a data storage system. A status indicating completion of the initialization is returned after setting initialization indicators associated with tracks of the device. The indicators indicate that the tracks of the device are to be initialized. As subsequent I/O operations for the device are processed, the tracks associated with the subsequent I/O operations are initialized prior to performing the I/O operation if the initialization indicators associated with the tracks are set. A background initialization task scans the initialization indicators and initializes tracks in accordance with the initialization indicators. Once a track has been initialized, its associated initialization indicator is cleared.

Formatting and initialization of device mirrors using initialization indicators

Two data operations, such as write operations, may be processed at a same time in which the two write operations operate on a same address range span. A first of the write operations may write to the first track and the last track in the span but not tracks therebetween. When processing the first write operation, a lock for the first track is obtained and the data is written to the first track data. A lock for the last track is obtained and it is determined whether all tracks between the first and last tracks are unlocked. If so, data is written to the last track. If not, steps of releasing and then reacquiring the lock for the last track and determining whether intervening tracks are locked are repeated until the intervening tracks are not locked. The last track is then written.

Techniques for performing data operations spanning more than two data partitions

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Shrewsbury, MA, United States of America

Pei-Ching Hwang