Symantec Corporation

Veritas Technologies LLC

Veritas Operating Corporation

Symantec Operating Corporating

Shailesh Marathe

Niranjan Sanjiv Pendharkar

Sumit Dighe

Anindya Banerjee

Angshuman Bezbaruah

Rajesh Chepuri

Anand A Kekre

Kedar Shrikrishna Patwardhan

Hari Krishna Vemuri

Amol Shivram Katkar

Viraj Kamat

Santosh Kalekar

Ronald S Karr

Subhojit Roy

Rahul M Fiske

Jai P Gahlot

Shirish Vijayvargiya

Sanjay Kumar Jain

Kirubakaran Kaliannan

Satyendra Thakur

Abhijit Toley

Ashish Laxmanrao Gawali

Vikas Goel

Prasanna V Wakhare

Asmita Jagtap

Venkata Tatavarty

Deodatta Barhate

Rishikesh Bhagwandas Jethwani

Pritam Bankar

Sushrut Gajbhiye

Roshan Kolhe

Vipul Jain

Jiang-Hsing Chu

Hasib Shaikh

Niranjan S Pendarkar

Narender Singh Mehra

Dhruv Bhatnagar

Gaurav Bhandarkar

Ajay Kumar

Mangesh Panche

Nitin Wankhede

Sumit Sharma

Bhooshan Thakar

Sumit Raghunath Dighe

Methods and the like according to the disclosure can include determining an information type of digital information, writing the digital information using a first process (in response to a determination that the information type of the digital information is a first information type), and, in response to a determination that the information type of the digital information is a second information type, determining erasure-coded parity information for the digital information and writing the digital information using a second process (where the digital information is to be written to erasure-coded storage). In the former case, the first process that includes writing the digital information to storage. The second process includes writing the digital information and the erasure-coded parity information to erasure-coded storage, without writing the digital information to a log.

Methods and systems for efficient erasure-coded storage systems

The disclosed computer-implemented method for distributing information across failure domains in servers may include (1) dividing, at a computing device, each of a quantity of 'K' failure domains (FDs) in a plurality of FDs into a quantity of 'P' portions, where the &#x201c;K&#x201d; FDs in the plurality of FDs are constituent parts of respective servers in a plurality of servers, &#x201c;P&#x201d; is less than &#x201c;K,&#x201d; and &#x201c;P&#x201d; is a sum of a quantity of &#x201c;M&#x201d; data portions and a quantity of &#x201c;N&#x201d; parity portions, (2) creating a quantity of &#x201c;K&#x201d; erasure-coded volumes in the &#x201c;K&#x201d; FDs, where each erasure-coded volume includes &#x201c;M&#x201d; data portions and &#x201c;N&#x201d; parity portions, and each portion in each erasure-coded volume is stored in a different FD and (3) combining the &#x201c;K&#x201d; volumes to create a file system. Various other methods, systems, and computer-readable media are also disclosed.

Systems and methods for distributing information across failure domains in servers

Disclosed herein are methods, systems, and processes to improve application performance in replication environments. In one embodiment, first application input/output (I/O) throughput and second application I/O throughput are associated with a data volume and are both sampled, with the first application I/O throughput being sampled while the data volume is set to an asynchronous write acknowledgement mode and the second application I/O throughput being sampled while the data volume is set to a synchronous write acknowledgement mode. A determination is made as to whether the asynchronous write acknowledgement mode or the synchronous write acknowledgement mode provides a higher application I/O throughput for the data volume. The data volume is then set to a preferred write acknowledgement mode that is selected, based on a result of the determining, from the asynchronous write acknowledgement mode and the synchronous write acknowledgement mode, and in certain embodiments, a mixed write acknowledgement mode.

Application performance in replication environments

Disclosed herein are methods, systems, and processes to perform input/output (I/O) fencing without dedicated arbitrators. A coordination storage identifier is stored in a storage device as metadata. The coordination storage identifier is associated with a node of a cluster coupled to the storage device, and an I/O fencing operation is performed using the coordination storage identifier.

Input/output (i/o) fencing without dedicated arbitrators

The disclosed computer-implemented method for switching replication modes in a volume replication system may include (i) in response to deciding to switch from a synchronous replication mode of a volume replication system to an asynchronous replication mode, changing, by a computing device, to the asynchronous replication mode, (ii) associating a new write request to write data to storage, (iii) determining, based on metadata of the existing write request, that the existing write request was issued in the synchronous replication mode, (iv) in response to determining that the existing write request was issued in the synchronous replication mode, processing the existing write request via the synchronous replication, and (v) processing the new write request via the asynchronous replication based on the metadata of the new write request. Various other methods, systems, and computer-readable media are also disclosed.

Systems and methods for switching replication modes in a volume replication system

The disclosed computer-implemented method for detecting bit rot in distributed storage devices having failure domains may include (1) receiving, at a computing device, a combination of data chunks created by adding, for each failure domain storing data chunks, data chunks from different stripes, (2) receiving a combination of parity chunks created by adding, for each failure domain storing parity chunks, parity chunks from the different stripes, (3) creating at least one new parity chunk from the combination of data chunks, and (4) identifying a presence of bit rot in the failure domains when the at least one new parity chunk does not match the combination of parity chunks. Various other methods, systems, and computer-readable media are also disclosed.

Systems and methods for detecting bit rot in distributed storage devices having failure domains

The disclosed computer-implemented method for transmitting data to a remote storage device may include (i) selecting, by a computing device, a bucket of a hash table for a data packet, (ii) adding a generation number to the data packet, (iii) transmitting the data packet to a remote storage device, (iv) adding the data packet to a send-list of the bucket, (v) receiving an acknowledgement packet for the data packet, (vi) determining that the acknowledgement packet corresponds to the generation number of the data packet, and (vii) removing the data packet from the send-list of the bucket. Various other methods, systems, and computer-readable media are also disclosed.

Systems and methods for transmitting data to a remote storage device

The disclosed computer-implemented method for distributing information across distributed storage devices may include (1) dividing, at a computing device, each of 'K' distributed storage devices (DSDs) in a plurality of DSDs into 'P' portions, where &#x201c;P&#x201d; is a sum of &#x201c;M&#x201d; data portions and &#x201c;N&#x201d; parity portions, (2) creating &#x201c;K&#x201d; erasure-coded volumes, where each volume includes one portion on different DSDs, &#x201c;M&#x201d; data portions, and &#x201c;N&#x201d; parity portions, and (3) combining the &#x201c;K&#x201d; volumes to create a file system. Various other methods, systems, and computer-readable media are also disclosed.

Systems and methods for distributing information across distributed storage devices

The disclosed computer-implemented method for managing quality of service may include (i) installing, at a network protocol layer, a latency monitoring plug-in that monitors latency at the network protocol layer as distinct from a storage layer beneath the network protocol layer, (ii) providing, by the latency monitoring plug-in, feedback reporting the latency at the network protocol layer to a quality of service engine that monitors characteristics of the storage layer such that the quality of service engine learns about the latency at the network protocol layer, and (iii) adjusting, by the quality of service engine, a calculation of system capacity, based on both the feedback from the latency monitoring plug-in reporting the latency at the network protocol layer and the monitored characteristics of the storage layer to enable an application to adhere to a service level agreement. Various other methods, systems, and computer-readable media are also disclosed.

Systems and methods for managing quality of service

Disclosed herein are methods, systems, and processes to improve application performance in replication environments. A read command configured to cause a read operation to be performed on a unit of storage in a data volume is received. A state of a lock is determined. The state of the lock indicates whether a write operation is ongoing, and the write operation results in data being written to a storage replication log and to the data volume. The write operation is ongoing because writing the data to the storage replication log and to the data volume has not completed. In response to a determination that the write operation is not ongoing, the read operation is allowed to be performed on the unit of storage.

Described herein are methods, systems, and processes to improve application performance in replication environments. A first write acknowledgement mode associated with a data volume is identified. The first write acknowledgement mode is one of multiple write acknowledgement modes. The write acknowledgement modes include a synchronous write acknowledgement mode and an asynchronous write acknowledgement mode. The data volume is switched from the first write acknowledgement mode to a second write acknowledgement mode that is part of the write acknowledgement modes, and is the synchronous write acknowledgement mode or the asynchronous write acknowledgement mode.

A computer-implemented method for enabling replication targets to reclaim unused storage space on thin-provisioned storage systems may include: 1) replicating data from a replication source to a replication target, 2) identifying unused storage space within the replicated data, 3) generating a reclamation request for reclaiming the unused storage space from a thin-provisioned storage system that provides thin-provisioned storage for the replication target, and then 4) issuing the reclamation request to the thin-provisioned storage system in order to reclaim the unused storage space from the thin-provisioned storage system. Various other related systems, methods, and configured computer-readable media are also disclosed.

Systems and methods for enabling replication targets to reclaim unused storage space on thin-provisioned storage systems

Various systems and methods for adjusting threshold access frequency based on cache pressure are disclosed. The threshold access frequency is adjusted based on a block of data in a storage volume that has an access frequency matching or exceeding the threshold access frequency. The threshold access frequency is used to determine whether the block of data should be inserted into the cache from the storage volume.

Cache insertion based on threshold access frequency

Multiple nodes of a cluster have associated non-shared, local caches, used to cache shared storage content. Each local cache is accessible only to the node with which it is associated, whereas the cluster-level shared storage is accessible by any of the nodes. Attempts to access the shared storage by the nodes of the cluster are monitored. Information is tracked concerning the current statuses of the local caches of the nodes of the cluster. Current tracked local cache status information is maintained, and stored such that it is accessible by the multiple nodes of the cluster. The current tracked local cache status information is used in conjunction with the caching functionality to determine whether specific nodes of the cluster are to access their local caches or the shared storage to obtain data corresponding to specific regions of the shared storage.

Providing local cache coherency in a shared storage environment

When a loss of connectivity between a first node in a cluster of nodes and a data store is detected, an input/output (I/O) request associated with an application that was executing on the first node is shipped to a second node in the cluster that is in communication with the data store. The application can be gracefully shut down on the first node, and the second node can execute the application and satisfy the I/O request.

Intelligent failover or shutdown of an application using input/output shipping in response to loss of connectivity to data storage in a cluster

Growing community of inventors

Pune, India

Shailesh Marathe