Symantec Corporation

Veritas Technologies LLC

Kirubakaran Kaliannan

Satyendra Thakur

Suhas Ashok Dantkale

Prasad Vadlamannati

Prasanta Ranjan Dash

Michael E Root

Yatin Nayak

Niranjan Sanjiv Pendharkar

Kedar Shrikrishna Patwardhan

Shailesh Marathe

Anirban Mukherjee

Venkata Sreenivasa Rao Nagineni

A computer-implemented method for shipping I/O operations to prevent replication failure may include 1) attempting to perform an I/O operation in a system configured to replicate data from a data cluster to another data cluster, 2) detecting a failure in at least part of the attempt to perform the I/O operation that threatens to fail the system's replication of data from the data cluster to the other data cluster, and, in response to detecting the failure, 3) shipping the I/O operation from a node originally responsible for servicing the I/O operation to another node to complete the I/O operation without failing the system's replication of data from the data cluster to the other data cluster. Various other methods, systems, and computer-readable media are also disclosed.

Systems and methods for shipping an I/O operation to prevent replication failure

Write operations are scheduled for multiple nodes in a shared storage cluster that supports volume replication. Requests are received from nodes for allocation of space for write operations in a replication log. In response to a received request, the current capacity of the requesting node to manage a backlog can be determined. The amount of space in the replication log allocated to the node is then calibrated to the node's capacity, thereby preventing self-throttling. A separate priority can be assigned to each volume, and space in the replication log assigned to each volume based on its priority. Nodes can target synchronous and other latency sensitive operations to higher priority volumes. A single global queue can be maintained to schedule write operations for all nodes, thereby providing a fair scheduling. A separate local queue can be maintained for each node, thereby providing specific levels of preference to specific nodes.

I/O scheduling and load balancing across the multiple nodes of a clustered environment

Various systems and methods for scheduling commands of a storage area network to minimize latency are disclosed. For example, one method involves receiving a command, where the command is received prior to this command being issued to one or more storage devices. The commands is configured to be issued to the one or more storage devices using one or more paths. The method also involves determining whether the command is a high impact (HI) command, where this determination is based, at least in part, on one or more criteria. In response to a determination that the command is an HI command, the method involves selecting a first path of the one or more paths as a primary HI path, where the selecting is based on one or more other criteria. The availability of the primary HI path to non-HI commands is determined based on one or more different criteria.

Scheduling of commands in a storage area network to minimize latency

I/O scheduling and load balancing across the multiple nodes of a clustered environment using a single global queue

I/O scheduling and load balancing across the multiple nodes of a clustered environment utilizing data volume based scheduling priorities

Systems and methods for shipping I/O operations to prevent replication failure

A method for storage reclamation in a shared storage device. The method includes executing a distributed computer system having a plurality of file systems accessing storage on a shared storage device, and initiating a reclamation operation by using a reclamation agent that accesses the shared storage device. The method further includes reading the file system data structure that represent unallocated storage blocks of one of the plurality of file systems that will undergo a reclamation operation. A plurality of I/O resources that are used to provide I/O to the unallocated storage blocks are then interrupted. Storage from the unallocated storage blocks is then reclaimed, and normal operation of the I/O resources that are used to provide I/O to the unallocated storage blocks is resumed.

Method and system for reclaiming storage on a shared storage device or independent of the mount state of a file system

A computer-implemented method for natural batching of I/O operations on a replication log may include: 1) identifying a replication log that records the order of writes within a cluster replication system, 2) determining that the replication log is unavailable, 3) queuing incoming I/O operations for the replication log in a single batch while the replication log is unavailable, 4) determining that the replication log has become available, 5) ceasing queuing of incoming I/O operations for the replication log based on the determination that the replication log has become available, and 6) grouping a plurality of I/O operations in the single batch for processing in parallel by assigning a same generation number to the plurality of I/O operations. Various other methods, systems, and computer-readable media are also disclosed.

Systems and methods for natural batching of I/O operations on a replication log

Storage systems and methods are presented. In one embodiment, a data storage resource management method comprises: performing a data update process, including communicating a data update input output packet between a primary storage resource and a secondary storage resource, wherein corresponding data updates in the secondary storage resource are a mirror of data updates in the primary storage resource; and performing a reclamation process, including: communicating reclamation information in a reclamation input output packet through the same interface as the data update input output packet, wherein the reclamation input output packet is communicated between the primary storage resource and the secondary storage resource; and reclaiming storage locations on the secondary storage resource in accordance with reclamation information in the reclamation input output packet communicated between the primary storage resource and secondary storage resource.

Data storage resource management systems and methods

A method for fast I/O path failure detection and cluster wide failover. The method includes accessing a distributed computer system having a cluster including a plurality of nodes, and experiencing an I/O path failure for a storage device. An I/O failure message is generated in response to the I/O path failure. A cluster wide I/O failure message broadcast to the plurality of nodes that designates a faulted controller. Upon receiving I/O failure responses from the plurality of nodes, an I/O queue message is broadcast to the nodes to cause the nodes to queue I/O through the faulted controller and switch to an alternate controller. Upon receiving I/O queue responses from the plurality of nodes, an I/O failover commit message is broadcast to the nodes to cause the nodes to commit to a failover and un-queue their I/O.

Fast I/O failure detection and cluster wide failover

A computer-implemented method for reclaiming storage space from deleted volumes on thin-provisioned disks may include: 1) identifying a deleted volume, 2) identifying storage space on a thin-provisioned disk that was allocated to the deleted volume, 3) saving information that identifies the storage space, 4) identifying a policy that specifies reclaiming the storage space asynchronously with respect to the deleted volume, and then 5) reclaiming the storage space asynchronously with respect to deletion of the volume in accordance with the policy. Various other methods, systems, and computer-readable media are also disclosed.

Systems and methods for reclaiming storage space from deleted volumes on thin-provisioned disks

A computer-implemented method for reclaiming storage space on striped volumes may include: 1) identifying a volume striped across a set of storage devices, 2) identifying a reclamation request to reclaim storage space allocated to the striped volume and then, for at least one device in the set of storage devices, 3) identifying stripes of storage on the device that are covered by the reclamation request, 4) creating a consolidated reclamation request for the device that identifies each stripe of storage on the device that is covered by the reclamation request, and then 5) issuing the consolidated reclamation request to the device. Various other methods, systems, and computer-readable media are also disclosed.

Growing community of inventors

Beaverton, OR, United States of America

Kirubakaran Kaliannan