Symantec Corporation

Symantec Operating Corporation

Microsoft Technology Licensing, LLC

Veritas Technologies LLC

Veritas Operating Corporation

Primaryio, Inc.

Dilip Madhusudan Ranade

Anindya Banerjee

Radha Shelat

Mukund Agrawal

Navin Kabra

Aalop Suresh Shah

Niranjan Sanjiv Pendharkar

BijayaLaxmi Nanda

Kedar Shrikrishna Patwardhan

Laxmikant Vithal Gunda

Anand Mitra

Sivaramakrishna Ramadugu Venkata

Nagaprabhanjan Bellari

Thomas E Saulpaugh

Ravisankar V Pudipeddi

Chirag Deepak Dalal

Karandeep Singh Anand

Sumit Kumar

Abid Ali

Pankaj Khanzode

Maneesh Pusalkar

Amit Singla

Manoj K Valiyaparambil

Shriram Wankhade

Sumit Kapoor

Vanita Prabhu

Charumathy Srinivasan

Sriram Balasubramaniam

Harish Chandra Pujari

Prasad Gajanan Joshi

Mukund Satish Agrawal

Storage locations in a first tier of a multi-tier storage system are allocated to a first set of data structures (e.g., inodes) in a first file set. A file that is stored in the first tier is associated with a first data structure of the first set. In response to determining that data in the file should be moved to a second tier of the multi-tier storage system, the file is associated with a second data structure in a second file set. The second data structure is allocated a storage location in the second tier. Consequently, two data structures are associated with the file. The data is copied from the first tier to the storage location in the second tier, and can be subsequently accessed using the second data structure.

Multi-tier storage using multiple file sets

Various systems and methods for performing a restore operation. For example, one method involves receiving information identifying a set of data objects to restore. The method also involves dividing the set of data objects into first and second subsets of data objects. After the first one of the subsets of data objects is restored from a backup computing system to a source computing system, the method involves determining whether a deduplication operation is performed on the source computing system. The method also involves delaying restoring the second subset until after the deduplication operation is performed on the source computing device.

Restoring data in deduplicated storage

An embodiment of the invention provides an apparatus comprising: a hypervisor comprising a virtual caching appliance (VCA) and an intermediate multipathing module that interfaces with VCA; wherein the intermediate multipathing module is configured to pass an I/O request from a virtual machine to the VCA; and wherein the VCA is configured to determine if the I/O request is to be passed from the VCA to a solid state storage or if the I/O request is to be passed from the VCA to a hard disk storage. Another embodiment of the invention provides a method comprising: passing an I/O request from a virtual machine to a virtual caching appliance (VCA) in a hypervisor; and determining if the I/O request is to be passed from the VCA to a solid state storage or if the I/O request is to be passed from the VCA to a hard disk storage.

Data caching system and method for hypervisor-based computer systems

Techniques for file system recovery are disclosed. In one particular exemplary embodiment, the techniques may be realized as a method for file system recovery comprising starting a recovery process for a failed node, utilizing the recovery process to read one or more committed but un-applied transactions from storage associated with the failed node, and recreating the one or more committed but un-applied transactions in memory associated with the recovery process.

Techniques for file system recovery

In an embodiment of the invention, an apparatus comprises: a hard disk drive input/output (HDD I/O) optimizer configured to receive a primary input/output (I/O) operation stream for a given cylinder in a permanent storage device, configured to schedule a secondary input/output (I/O) operation stream that is pending on the same given cylinder or that is pending on an adjacent cylinder that is adjacent to the given cylinder, and configured to allocate free space from the same given cylinder or from the adjacent cylinder for the secondary I/O operation stream that is pending.

Maximize IO throughput in hybrid storage solution

A file system that includes multiple logical devices can be subdivided into multiple containers. The containers each include respective non-overlapping sets of the logical devices. An amount of memory allocated to a container is dynamic. A set of the containers can be selected for a file system consistency check. The file system consistency check is performed on only the set of the containers instead of on the entire file system.

File system consistency check on part of a file system

A region of memory is logically divided into a number of segments, each of which is logically divided into a number of blocks. Blocks are allocated sequentially. A head pointer and a tail pointer demarcate the section of allocated blocks. As allocated blocks are added, the tail pointer is moved so that it remains at the end of the section of allocated blocks. If the tail pointer is within a threshold distance of the head pointer, then the head pointer is moved from its current position to a new position, and the allocated blocks between the current and new positions are freed (deallocated and/or erased). Thus, writes to the memory can be performed sequentially, and blocks can be freed in advance of when they are actually needed.

Sequential block allocation in a memory

Various systems and methods for placing a virtual machine on one of a plurality of candidate physical machines. For example, one method can involve generating a list that comprises entries for a virtual machine. Each entry in the list indicates a portion of data that is associated with the virtual machine. The method then involves calculating a number of common entries between the list and each of a plurality of candidate lists, where a common entry is an entry that is included in the respective candidate list and in the list. Each candidate list is associated with a computing device. In response to detecting which candidate list has the most common entries, the method involves assigning the virtual machine to the computing device associated with that candidate list.

Placement of virtual machines based on page commonality

Various systems and methods selectively generate a point-in-time copy of less than all of the data items within a collectively-managed set of data items. One method involves detecting a modification to a first unit of data within a collectively managed set, subsequent to generation of a selective snapshot of the collectively managed set, and then accesses a first tag associated with the first unit of data. Based on a value of the first tag, the method determines whether the first unit of data is included in a subset of the collectively managed set. The subset includes at least two of the units of data and fewer than all of the units of data in the collectively managed set. Based upon whether the unit of data is included in the subset, the method selects whether to preserve an original value of the first unit of data.

System and method for generating a point-in-time copy of a subset of a collectively-managed set of data items

Systems and methods for copy on write storage conservation are presented. In one embodiment a copy on write storage conservation method includes creating and mounting a snapshot; mounting a snapshot; monitoring interest in the snapshot; initiating a copy on write discard process before a backup or replication is complete; and deleting the snapshot when the backup or replication is complete. In one embodiment the method also includes marking a file as do not copy on write. In one embodiment, the copy on write discard process includes discarding copy on write data when a corresponding read on the file in the snapshot is successful. Initiating a copy on write discard process can be done at a variety of levels (e.g., a file level, an extent level, a block-level, etc.).

Copy on write storage conservation systems and methods

Methods and systems are disclosed for backup using a metadata virtual hard drive (VHD) and a differential VHD. A particular system includes a memory device that stores files and a backup agent configured to detect changes to the files. The system includes a translation module configured to translate the detected changes into VHD formatted changes and a VHD module configured to write the VHD formatted changes to a metadata VHD stored at the memory device. The VHD module is also configured to generate a differential VHD based on the metadata VHD. A network interface at the system is configured to transmit the metadata VHD and the differential VHD to a remote storage device.

Backup using metadata virtual hard drive and differential virtual hard drive

A method for replicating data in cluster environments may include (1) identifying a cluster of nodes configured to replicate common storage of the cluster, (2) identifying a first write operation issued by a first node to the common storage, (3) identifying a second write operation issued by a second node to the common storage after the first write operation, (4) identifying a completion time of the first write operation, (5) identifying a start time of the second write operation, (6) identifying a maximum potential skew between the first system clock and the second system clock, (7) determining that the first and second write operations are mutually independent by determining that the start time of the second write operation precedes the completion time of the first write operation by a span greater than the maximum potential skew, and then (8) replicating the first and second write operations in parallel.

Systems and methods for replicating data in cluster environments

A method for managing virtual disk data storage may include: 1) identifying first and second virtual storage disks on a physical storage system; 2) identifying relocatable data in the first and second virtual storage disks; 3) comparing the relocatable data from the first and second virtual storage disks to identify one or more data objects in the first virtual storage disk that are identical to one or more data objects in the second virtual storage disk; 4) physically relocating the data objects from the first virtual storage disk to create a first chunk of data without changing a logical state of data in the first virtual storage disk; and 5) physically relocating the data objects from the second virtual storage disk to create a second chunk of data that is identical to the first chunk of data without changing a logical state of data in the second virtual storage disk.

Systems and methods for managing virtual storage disk data

Described is a technology by which data is efficiently and securely stored in a single instance store. A hash value is computed from data in its unencrypted form. The hash value is used to reference a single instance of that data when stored in its encrypted form. In this manner, duplicate data blocks are detectable independent of their encryption, yet stored in an encrypted form in a single instance store. In one aspect, context information for decrypting the encrypted data is stored in association with the data. When the client wants to restore the data, the client sends the hash value for that block to the single instance store service. The service returns the block and the associated context information. The client uses the context information to decrypt the block. For example, the context may comprise a key identifier which the client uses to lookup the correct key.

Single instance storage of encrypted data

A computer-implemented method for creating snapshots may include identifying a request to take a snapshot of a primary volume of data. The computer-implemented method may also include identifying a write-once block device configured to receive data for the snapshot. The computer-implemented method may further include identifying an attempt to write to a block of the primary device. The computer-implemented method may additionally include copying the block to the write-once block device before allowing the write attempt to write to the block of the primary volume. Various other methods, systems, and computer-readable media are also disclosed.

Growing community of inventors

Pune, India

Dilip Madhusudan Ranade