Emc IP Holding Company LLC

Emc Corporation

Shuang Liang

Mahesh Kamat

Philip N Shilane

Grant R Wallace

Akshay Narayan Muramatti

Jayasekhar Konduru

Bhimsen Bhanjois

Rahul Ugale

Dheer Moghe

Satish Visvanathan

Shyam Burkule

Yiqiang Ding

Arun Keshavamurthy

Ganesh Karuppur Rajagopalan

Pragyashree Gogoi

A data management device includes a persistent storage and a processor. The persistent storage includes an object storage. The processor segments a file into file segments. The processor generates meta-data of the file segments. The processor stores a portion of the file segments in a data object of the object storage. The processor stores a portion of the meta-data of the file segments in a meta-data object of the object storage.

Metadata separated container format

Systems and methods for managing content in a flash memory and to managing a lifespan of the flash memory. The lifespan is managed by throttling writes when usage exceeds certain quotas. The throttling may be performed in a cooperative manner such that the clients writing to the flash memory can implement their own throttling. The quotas are not rigid and allow flexibility to certain situations. When excessive quota is used, future quotas can be managed to bring the overall usage into an expected range.

Managing lifespan of a flash memory

A data management device includes a cache for a data storage device and a processor. The cache includes cache devices that store a block set. The processor obtains a cache modification request that specifies a first block of the block set, updates a copy of a header of the block set in each of the cache devices based on the modification request, updates a copy of meta-data of the block set in each of the cache devices based on the cache modification request, and updates the first block in a first cache device of the cache devices based on the cache modification request.

Metadata protected sparse block set for SSD cache space management

According to some embodiment, a storage system provides metadata containers and an object storage that includes one or more objects. Each of the objects includes one or more data segments of a file object and each of the metadata containers includes one or more fingerprints for identifying the data segments in the object. The system loads some of the objects into a memory device of the storage system. For each of the loaded objects, the system traverses some of the metadata containers and performs a lookup operation to determine whether each data segment in the object is identified by a fingerprint from the traversed metadata containers.

Method and system for data consistency verification in a storage system

One embodiment is related to a method for redistributing cache space, comprising: determining utility values associated with all of a plurality of clients, each client being associated with a respective utility value, the utility value being indicative of an efficiency of cache space usage of the associated client; and redistributing cache space among the plurality of clients based on the utility values.

Dynamically redistribute cache space based on time savings

One embodiment is related to a method for redistributing cache space, comprising: determining a request by a first client of a plurality of clients for additional cache space, each of the plurality of clients being associated with a guaranteed minimum amount (MIN) and a maximum amount (MAX) of cache space; and fulfilling or denying the request based on an amount of cache space the first client currently occupies, an amount of cache space requested by the first client, and the MIN and the MAX cache space associated with the first client.

Dynamically redistribute cache space with min-max technique

A method for upgrading a file system in a data storage environment is provided. A storage system identifies a set of boundaries of one or more sets of hard disks based on a first block management data structure (BMDS), where the first BMDS includes information describing a storage volume representing the one or more sets of hard disks. For each identified boundary, the storage system identifies a data block range of a set of data blocks, where the data block range includes metadata of one set of hard disks that is stored on the set of data blocks. Further, the storage system concurrently generates a plurality of second BMDSs, each of the second BMDS corresponding to one of the sets of hard disks, including simultaneously retrieving metadata of the sets of hard disks, where the second BMDSs are constructed based on the retrieved metadata, representing an upgraded file system.

Method for parallel file system upgrade in virtual storage environment

A data storage device includes virtual storage devices, hosted by physical storage devices, and a processor. The processor obtains a data storage request, divides a file specified by the data storage request into blocks, and stores the blocks in the virtual storage devices based on an input output (IO) limitation of the virtual storage devices.

Method for efficient load balancing in virtual storage systems

A computer-implemented method for storing backup data includes receiving, by a computing system, data associated with a file to be backed up; performing, by the computing system, de-duplication on the file to remove duplicated data and to generate unique backup data; receiving, by the computing system, a file handle based on opening a block-based storage file; storing, by the computing system, a metadata container in the block-based storage file stripe aligned; and storing, by the computing system, a data container in the block-based storage file stripe aligned, wherein the metadata container and the data container are associated with a set of objects, and wherein the data container includes the unique backup data.

Object storage in stripe file systems

A method, article of manufacture, and apparatus for scaling an index on a solid state drive in a deduplicated storage system is discussed. The index may be scaled as index hash buckets approach capacity, or as new solid state drives are added to the system. The hash buckets may be mapped to HDD hash buckets, which are stored on a hard drive.

Scaling an SSD index on a deduplicated storage system

A first tree data structure is used to track an allocation state for each block included in a first set of storage blocks. Upper level nodes in a given tree present the allocation state of connected lower level nodes in the given tree, such that each allocation state indicates whether any associated storage blocks are free. A second tree data structure is used to track an allocation state for each block included in a second set of storage blocks. The first tree data structure and the second tree data structure each have a number of leaf nodes corresponding to a maximum number of blocks that can be included in a superset of storage blocks, wherein the first set of storage blocks and second set of storage blocks are included in the superset of storage blocks. An allocation bitmap associated with the superset of storage blocks is used to track allocation states of storage blocks in the superset, wherein each leaf node of a specified tree is associated with a plurality of associated locations in the allocation bitmap.

Memory efficient block allocation map to support online growth of different storage attributes

A single virtual storage device file system that abstracts multiple RAID groups of physical storage devices into one virtual device and one first blockset having a plurality of data blocks in a contiguous linear address space is converted into a multiple virtual device file system that abstracts the multiple RAID groups of physical storage devices as separate multiple virtual storage devices each having a separate second blockset and address space, by migrating data in allocated blocks at boundaries of the physical storage device groups to free blocks, partitioning the first blockset at the boundaries into the multiple second blocksets, updating the block metadata of each block, and rebuilding the file system using the block metadata to generate second blockset metadata.

Invulnerable data movement for file system upgrade

Physical storage is replaced online in a data integrity storage system comprising RAID groups of physical disks in separate enclosures (shelves). All disks of a RAID group are located on a corresponding shelf, and each shelf is mapped by an internal file system to a separate independent logical address space partitioned into a plurality of blocks forming a blockset containing data and metadata. Source shelf disk data is moved online to disks of a target shelf using invulnerable data movement that ensures the integrity of the data, and source shelf blockset metadata is migrated to a corresponding target shelf blockset. After verifying the correctness of the target data and metadata, the source shelf and blockset are removed.

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Sunnyvale, CA, United States of America

Shuang Liang