Abstract: Embodiments described herein provide techniques for maintaining consistency in a distributed system (e.g., a distributed secondary storage system). According to one embodiment of the present disclosure, a first set of file system objects included in performing the requested file system operation is identified in response to a request to perform a file system operation. An update intent corresponding to the requested file system operation is inserted into an inode associated with each identified file system object. Each file system object corresponding to the inode is modified as specified by the update intent in that inode. After modifying the file system object corresponding to the inode, the update intent is removed from that inode.

Abstract: A method and system for performing incremental backup of a network attached storage (NAS) device are described. A storage capture instance associated with a first time instance is received from a network attached storage device. At least a portion of metadata of tracked network packets associated with the network attached storage device is also received. At least one changed content item of the network attached storage device that has changed since the first time instance is identified by analyzing the at least the portion of the metadata of the tracked network packets received. An incremental backup of the network attached storage device is performed at a second time instance based at least in part on the at least one changed content item identified.

Abstract: Embodiments described herein provide techniques for maintaining consistency in a distributed system (e.g., a distributed secondary storage system). According to one embodiment of the present disclosure, a first set of file system objects included in performing the requested file system operation is identified in response to a request to perform a file system operation. An update intent corresponding to the requested file system operation is inserted into an inode associated with each identified file system object. Each file system object corresponding to the inode is modified as specified by the update intent in that inode. After modifying the file system object corresponding to the inode, the update intent is removed from that inode.

Abstract: An improved architecture is provided which enables significant convergence of the components of a system to implement virtualization. The infrastructure is VM-aware, and permits scaled out converged storage provisioning to allow storage on a per-VM basis, while identifying I/O coming from each VM. The current approach can scale out from a few nodes to a large number of nodes. In addition, the inventive approach has ground-up integration with all types of storage, including solid-state drives. The architecture of the invention provides high availability against any type of failure, including disk or node failures. In addition, the invention provides high performance by making I/O access local, leveraging solid-state drives and employing a series of patent-pending performance optimizations.

Abstract: A method and system for performing incremental backup of a network attached storage (NAS) device are described. A storage capture instance associated with a first time instance is received from a network attached storage device. At least a portion of metadata of tracked network packets associated with the network attached storage device is also received. At least one changed content item of the network attached storage device that has changed since the first time instance is identified by analyzing the at least the portion of the metadata of the tracked network packets received. An incremental backup of the network attached storage device is performed at a second time instance based at least in part on the at least one changed content item identified.

Abstract: A computer implemented method implemented with a processor for assigning a unique identifier for a data item initially deployed at a node of a networked environment includes determining a unique node identifier for the node of the networked environment, atomically modifying a local counter value at the node of the networked environment, and appending the unique node identifier to the atomically modified local counter value at the node of the networked environment to form a unique ID for the data item.

Abstract: An improved architecture is provided which enables significant convergence of the components of a system to implement virtualization. The infrastructure is VM-aware, and permits scaled out converged storage provisioning to allow storage on a per-VM basis, while identifying I/O coming from each VM. The current approach can scale out from a few nodes to a large number of nodes. In addition, the inventive approach has ground-up integration with all types of storage, including solid-state drives. The architecture of the invention provides high availability against any type of failure, including disk or node failures. In addition, the invention provides high performance by making I/O access local, leveraging solid-state drives and employing a series of patent-pending performance optimizations.

Abstract: Systems, methods, and computer program products for managing a consensus group in a distributed computing cluster, by determining that an instance of an authority module executing on a first node, of a consensus group of nodes in the distributed computing cluster, has failed; and adding, by an instance of the authority module on a second node of the consensus group, a new node to the consensus group to replace the first node. The new node is a node in the computing cluster that was not a member of the consensus group at the time the instance of the authority module executing on the first node is determined to have failed.

Abstract: A method and apparatus for maintaining file system consistency in a distributed system using version vectors is presented. A method generally includes comparing incarnation and transaction identifiers of a current version vector associated with a file with incarnation and transaction identifiers of a last completed version vector associated with the file. Upon determining that a current version vector reflects operations on the file that are either earlier than or the same as the identifiers in the last completed version vector, the node performing one or more file system operations on the file.

Abstract: A request to write data corresponding to at least a first portion of a file is received. It is determined whether to perform the request either as an in-place write or as an out-of-place write. Performing the in-place write comprises performing a write to a low latency storage device, and performing the out-of-place write comprises performing a write to a higher latency storage device. The request is performed as either the in-place write or the out-of-place write based on the determination. Performing the request as the in-place write includes writing the data to a first location on a storage tier storing the first portion of the file, and performing the request as the out-of-place write includes writing the data to a second location on one of a plurality of storage tiers of a computing node, other than the first location.

Abstract: A size associated with a content file is determined to be greater than a threshold size. Contents of the content file split across a plurality of component files are stored. Metadata, for the content file, is updated to reference a plurality of component file metadata structures for the component files. A node of the metadata is configured to track different sizes of portions of the content file stored in different component files of the plurality of component files. File metadata of the content file is split across the plurality of component file metadata structures and each component file metadata structure of the plurality of component file metadata structures specifies a corresponding structure organizing data components for a corresponding portion of the content file.

Abstract: Techniques for cloning, writing to, and reading from file system metadata. Cloning involves identifying a first set of pointers included in a first root node in a file system metadata tree structure that stores file system metadata in leaf nodes of the tree structure, creating a first copy of the first root node that includes the first set of pointers, creating a second copy of the first root node that includes the first set of pointers, associating the first copy with a first view, and associating the second copy with a second view. Reading generally involves traversing the tree structure towards a target leaf node that contains data to be read. Writing generally involves traversing the tree structure in the same manner, but also creating copies of any nodes to be modified if those nodes are deemed to have a different treeID than a particular root node.

Abstract: An improved architecture is provided which enables significant convergence of the components of a system to implement virtualization. The infrastructure is VM-aware, and permits scaled out converged storage provisioning to allow storage on a per-VM basis, while identifying I/O coming from each VM. The current approach can scale out from a few nodes to a large number of nodes. In addition, the inventive approach has ground-up integration with all types of storage, including solid-state drives. The architecture of the invention provides high availability against any type of failure, including disk or node failures. In addition, the invention provides high performance by making I/O access local, leveraging solid-state drives and employing a series of patent-pending performance optimizations.

Abstract: A method for performing lockless modifications during a rolling upgrade of a column family from an old column family version to a new column family version in a NoSQL database.

Abstract: Techniques are disclosed which allow a secondary storage system to provide data to non-production workloads in conjunction with performing data backup and protection tasks. As disclosed, a secondary storage system exposes backup data stored by the secondary storage system to other workloads, such as test and development applications, data analytics, etc. These non-production workloads can run at the same time the secondary storage system provides backup services to a primary storage system. This consolidation eliminates the need for an enterprise to deploy separate storage clusters for analytics, test and development applications, etc. and eliminates unnecessary copies of data.

Abstract: A method and apparatus for maintaining file system consistency in a distributed system using version vectors is presented. A method generally includes comparing incarnation and transaction identifiers of a current version vector associated with a file with incarnation and transaction identifiers of a last completed version vector associated with the file. Upon determining that a current version vector reflects operations on the file that are either earlier than or the same as the identifiers in the last completed version vector, the node performing one or more file system operations on the file.

Abstract: A request to write data corresponding to at least a first portion of a file is received. It is determined whether to perform the request either as an in-place write or as an out-of-place write. Performing the in-place write comprises performing a write to a low latency storage device, and performing the out-of-place write comprises performing a write to a higher latency storage device. The request is performed as either the in-place write or the out-of-place write based on the determination. Performing the request as the in-place write includes writing the data to a first location on a storage tier storing the first portion of the file, and performing the request as the out-of-place write includes writing the data to a second location on one of a plurality of storage tiers of a computing node, other than the first location.

Abstract: Disclosed is an improved approach for implementing and maintaining writable snapshots. An efficient approach is provided for implementing snapshots that can be used to immediately create snapshots without incurring any detectable delays in providing access to the new snapshots. Also described are improved metadata structures that can be used to implement and maintain the writable snapshots.

Abstract: Techniques for cloning, writing to, and reading from file system metadata. Cloning involves identifying a first set of pointers included in a first root node in a file system metadata tree structure that stores file system metadata n leaf nodes of the tree structure, creating a first copy of the first root node that includes the first set of pointers, creating a second copy of the first root node that includes the first set of pointers, associating the first copy with a first view, and associating the second copy with a second view. Reading generally involves traversing the tree structure towards a target leaf node that contains data to be read. Writing generally involves traversing the tree structure n the same manner, but also creating copies of any nodes to be modified if those nodes are deemed to have a different treeID than a particular root node.

Abstract: Disclosed is an improved approach to implement I/O and storage device management in a virtualization environment. According to some approaches, a Service VM is employed to control and manage any type of storage device, including directly attached storage in addition to networked and cloud storage. The Service VM implements the Storage Controller logic in the user space, and can be migrated as needed from one node to another. IP-based requests are used to send I/O request to the Service VMs. The Service VM can directly implement storage and I/O optimizations within the direct data access path, without the need for add-on products.