Emc Corporation

Emc IP Holding Company LLC

Khang Can

Xiangping Chen

Mark K Ku

Qin Tao

David W Harvey

Dennis Thomas Duprey

Dean D Throop

Manish Madhukar

Miles Aram De Forest

Thomas Earl Linnell

Kevin Bangyen Jiang

Xiaoye Jiang

Harold Martin Sandstrom

Monica Chaudhary

Sadagopan Balaraman

Siyu Zhou

Qin Tau

Jun Zeng

A method is used in managing data accesses in storage systems. An access path to a storage object is evaluated. The storage object is associated with a first storage processor of a storage system for providing access to the storage object. The storage object is accessed using a second storage processor of the storage system. The storage system includes source and destination storage pools configured such that performance characteristics associated with the source storage pool is different from performance characteristics associated with the destination storage pool. The storage object resides in the source storage pool associated with the first storage processor. Based on the evaluation, the access path of the storage object is changed to the second storage processor based on a policy. The policy determines available storage space in the destination storage pool associated with the second storage processor for migrating the storage object to the destination storage pool.

Managing data accesses in storage systems

A method is used in managing data relocation in storage systems. Data access activity information is gathered for a set of slices of a storage tier in a data storage system for migrating the set of slices from the storage tier to another storage tier. The data storage system includes a first storage tier and a second storage tier configured such that performance characteristics associated with the first storage tier is superior to the second storage tier. Based on a pattern indicated by the data access activity information, a temperature for the set of slices is determined by applying a predictive analysis technique. Based on the determination, relocation of data is effected in the storage system.

Managing data relocation in storage systems

A technique for managing temporal data placement in data storage systems is disclosed. An application program interface (API) is provided, where a host application is configured to communicate sub-LUN data segment location, application configuration tiering, and timing parameter information to the API. The sub-LUN data segment location, application configuration tiering, and timing parameter information is transmitted to the data storage system via an out-of-band communications path. The sub-LUN data segment location, application configuration tiering, and timing parameter information is received at the data storage system and associated with the corresponding LUN. A timing estimate for implementing sub-LUN data segment relocation is generated based on system derived tiering information and recent relocation timing information. Relocation of the sub-LUN data segment is scheduled such that the sub-LUN data segment is relocated to a tier corresponding to the application configuration tiering information during the time period associated with the timing parameter.

Managing time scheduled data placement in data storage systems

Described are techniques for determining slice sizes. First I/O workload information is received for a slice having a corresponding logical address subrange of a logical address range of a logical device. The corresponding logical address subrange is a first size denoting a size of the slice at a first point in time when the slice has a current I/O workload denoted by the first I/O workload information. It is determined, in accordance with the first I/O workload information, whether to adjust the size of the slice. Responsive to determining to adjust the size of the slice, first processing is performed that adjusts the size of the slice such as by partitioning the slice or merging the slice with one or more other adjacent slices.

Techniques for dynamically adjusting slice size

A method is used in balancing I/O load on data storage systems. A slice is selected from a first storage container of a storage tier. The storage tier includes a second storage container. The slice is relocated from the first storage container of the storage tier to the second storage container of the storage tier, where I/O load of the first storage container is greater than I/O load of the second storage container.

Balancing I/O load on data storage systems

A method, computer program product, and computing system for comparing at least one performance benchmark to at least one performance indicator for a front end LUN. If the at least one performance indicator exceeds the at least one performance benchmark, the failure domain of the front end LUN is reduced. If the at least one performance indicator does not exceed the performance benchmark, the failure domain of the front end LUN is increased.

System and method for LUN adjustment

A method, computer program product, and computing system for identifying at least one misassigned slice that is associated with a first data tier and is located in a first front end LUN. The at least one misassigned slice is being accessed contrary to the first data tier. The failure domain of the first front end LUN is determined. At least one replacement slice that is associated with a second data tier and is located in a second front end LUN is identified based, at least in part, upon the failure domain of the first front end LUN. The at least one misassigned slice is moved to the second front end LUN. The at least one replacement slice is moved to the first front end LUN.

A method is used in measuring data access activity. I/O data is analyzed that describes I/O activity for a slice of a logical volume. Based on the I/O data, a first value of data access activity is determined for the slice corresponding to a first time period, and a second value of data access activity is determined corresponding to a second time period. From the first and second values, an exponential moving average of data access activity is derived for the slice.

Measuring data access activity

Methods and systems are disclosed for relocating data in a physical storage pool comprising a plurality of storage tiers having differing performance characteristics, the physical storage pool being mapped into one or more logical units, each logical unit comprising a plurality of logical slices of data storage. The methods and systems can involve receiving a relocation list, the relocation list including, for each of a plurality of logical slices, a slice identifier, a temperature value, and a current physical location, determining a destination tier for each logical slice on the relocation list, evaluating for each logical slice on the relocation list a performance gain expected to be achieved by moving the logical slice from its current physical location to a new location in the destination tier, and relocating data in a logical slice from its current physical location to the new location based on the evaluation.

Automated data relocation among storage tiers based on storage load

A method is used in applying data access activity measurements. A slice relocation candidate list is generated which identifies slices to be relocated along with respective destination tier information. Slices in a pool are matched to respective matching tiers based on the slices' respective temperatures and tier preferences. Based on whether a current tier for a slice differs from the matching tier for the slice, the slice is listed in the relocation candidate list.

Applying data access activity measurements

A storage processor of a data storage system includes a data relocation task scheduler that provides system limit control on the execution of data relocation requests. The data relocation task scheduler also provides fairness and concurrency limit enforcement by scheduling relocation requests from different provisioning domains, such as storage pools, in a fair manner. For example, the data relocation task scheduler includes stackable sets of pending task queues that store incoming data relocation requests. The data relocation task scheduler applies an iteration scheme to remove data relocation requests from the pending task queues thereby providing scheduling fairness among the queues and among the different provisioning domains within the data storage system. The data relocation task scheduler is configured to receive updated policies that control both system-wide data relocation resource consumption and scheduling fairness among the queues during operation and dynamically adjust current policies with the updated policies.

Scheduling data relocation activities using configurable fairness criteria

A method and apparatus for managing at least one logical volume in a computer system that includes a processor, a storage system, and a plurality of paths coupling the processor to the storage system. The storage system stores a plurality of logical volumes that includes the at least one logical volume, and the at least one logical volume is accessible to the processor over at least two paths. The processor includes a mapping layer that assigns the logical volumes to store particular volumes of data. At least two distinct native names are created for the at least one logical volume, each native name corresponding to one of the paths over which the logical volume is accessible to the processor. A pseudoname is created for the distinct native names, and represents the at least one logical volume in a manner that is independent of the paths over which the logical volume is accessible to the processor. The pseudoname and the at least two native names each is made available to the mapping layer for assignment to store a volume of data, so that the mapping layer may assign the at least one logical volume to store a particular volume of data by assigning the pseudoname or either of the native names to store the particular volume of data.

Growing community of inventors

Framingham, MA, United States of America

Khang Can