Abstract: A system can maintain information indicative of prohibited computer operations, wherein the information is accessible to respective computing clusters of a group of computing clusters, and wherein the information is stored separately from the group of computing clusters. The system can obtain, by a service of a first computing cluster of the group of computing clusters, the information. The system can, in response to receiving, at the first computing cluster, a request to perform an operation on a first computer of the first computing cluster, in response to determining, based on the information, that the operation is prohibited, prevent the operation from occurring; and, in response to determining, based on the information, that the operation is not prohibited, permit the operation to occur.

Abstract: A system can maintain information indicative of prohibited computer operations, wherein the information is accessible to respective computing clusters of a group of computing clusters, and wherein the information is stored separately from the group of computing clusters. The system can obtain, by a service of a first computing cluster of the group of computing clusters, the information. The system can, in response to receiving, at the first computing cluster, a request to perform an operation on a first computer of the first computing cluster, in response to determining, based on the information, that the operation is prohibited, prevent the operation from occurring; and, in response to determining, based on the information, that the operation is not prohibited, permit the operation to occur.

Abstract: A Software Defined Network Attached Storage (SDNAS) executes on a storage system to provide access to shared file systems, referred to as “shares”, on the storage system. Users access the shares using protocol clients. To enable the SDNAS to provide differentiated prioritization between the various shares, a share priority table is maintained by the SDNAS. As shares are created, or optionally after the shares have been created, each share is assigned a share priority which is stored in the share priority table. When an IO operation is received from a protocol client on a share, the SDNAS process determines a share priority value of the share from the share priority table. The share priority value is used to specify an IO priority which used by the operating system scheduling mechanism to schedule the IO operation and to establish a CPU priority for the IO operation.

Abstract: A Software Defined Network Attached Storage (SDNAS) executes on a storage system to provide access to shared file systems, referred to as “shares”, on the storage system. Users access the shares using protocol clients. To enable the SDNAS to provide differentiated prioritization between the various shares, a share priority table is maintained by the SDNAS. As shares are created, or optionally after the shares have been created, each share is assigned a share priority which is stored in the share priority table. When an IO operation is received from a protocol client on a share, the SDNAS process determines a share priority value of the share from the share priority table. The share priority value is used to specify an IO priority which used by the operating system scheduling mechanism to schedule the IO operation and to establish a CPU priority for the IO operation.

Abstract: Files can be managed to mitigate undesirable reading of files from secondary storage component (SSC) associated with a storage system comprising primary storage component (PSC). File management component (FMC) can determine file identifiers for files stored in SSC and store them in reference files associated with such files. FMC can determine file identifiers for files stored in PSC and store them in a file entry data store. In response to a client request, FMC can determine whether a local file stored in PSC is a copy of an archived file stored in SSC based on whether the respective file identifiers of the archived file and local file or snapshot of the local file match. If there is a suitable match, FMC can read the snapshot of the local file and provide it to client device; if not, FMC can read the archived file and provide it to client device.

Abstract: A Software Defined Network Attached Storage (SDNAS) executes on a storage system to provide access to shared file systems, referred to as “shares”, on the storage system. Users access the shares using protocol clients. A share priority table is maintained by the SDNAS and used to specify share priorities on the storage system. A share priority adjustment process is used to dynamically adjust the share priority values based on average usage values computed using a weighted usage function, and optionally based on limited ranges. The weighted usage function considers the average number of protocol client connections on the share, the average number of read operations on the share, whether the share supports continuous availability, and other factors. The adjusted share priority values are used to specify IO priorities which used by the operating system scheduling mechanism to schedule the IO operations and to establish CPU priorities for the IO operations.

Abstract: Files can be managed to mitigate undesirable reading of files from secondary storage component (SSC) associated with a storage system comprising primary storage component (PSC). File management component (FMC) can determine file identifiers for files stored in SSC and store them in reference files associated with such files. FMC can determine file identifiers for files stored in PSC and store them in a file entry data store. In response to a client request, FMC can determine whether a local file stored in PSC is a copy of an archived file stored in SSC based on whether the respective file identifiers of the archived file and local file or snapshot of the local file match. If there is a suitable match, FMC can read the snapshot of the local file and provide it to client device; if not, FMC can read the archived file and provide it to client device.

Abstract: 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.

Abstract: Disclosed herein are various embodiments that perform application-aware input/output (I/O) fencing operations, certain of which embodiments include, in response to detection of a network partition event in a cluster, determining a first application weight, determining whether the first one or more application instances should be delayed in a cumulative fencing race, performing the cumulative fencing race (in response to a determination that the first one or more application instances should be delayed in the cumulative fencing race), and performing the cumulative fencing race without introducing the delay with regard to the first one or more application instances (in response to a determination that the first one or more application instances should not be delayed in the cumulative fencing race).

Abstract: Implementations are provided herein for optimizing the usage of cluster resources in a cluster of nodes operating as a distributed file system. A node relative capacity table can be generated that inventories the total capacity of each node within the cluster of nodes. Each node can then be dynamically monitored for usage of node resources. A node available capacity table can be dynamically populated with the amount of available capacity each node has for compute, memory usage, and network bandwidth. When clients connect to the distributed file system, they can be directed to have their requests serviced by nodes with greater available capacity based on policy.

Abstract: Disclosed herein are various embodiments that perform application-aware input/output (I/O) fencing operations, certain of which embodiments include, in response to detection of a network partition event in a cluster, determining a first application weight, determining whether the first one or more application instances should be delayed in a cumulative fencing race, performing the cumulative fencing race (in response to a determination that the first one or more application instances should be delayed in the cumulative fencing race), and performing the cumulative fencing race without introducing the delay with regard to the first one or more application instances (in response to a determination that the first one or more application instances should not be delayed in the cumulative fencing race).

Abstract: Disclosed herein are methods, systems, and processes to perform application aware input/output (I/O) fencing operations. Performing such an application aware I/O fencing operation includes installing an identifier that identifies an instance of an application with a node on which the instance of the application is executing, on coordination points. A weight assigned to the instance of the application is determined, and the instance of the application is terminated based on the weight.

Abstract: Various systems, methods, and processes to optimize partition arbitration are disclosed. In response to a cluster being partitioned into multiple network partitions, a determination is made, using a first node in a first network partition, whether the first node wins one or more coordination points. The determination of the first node is then transmitted to a second node in the first network partition. Further, another determination is made using the second node whether the second node wins one or more other coordination points other than the one or more coordination points won by the first node.

Abstract: Various systems, methods, and processes to optimize input/output (I/O) fencing operations in systems that implement coordination points are presented. A matrix is generated. The matrix includes information indicating the accessibility of one or more coordination points by a node. The method then transmits the matrix to one or more other nodes.

Abstract: Various methods, systems, and processes to prevent data corruption caused by a pre-existing split brain condition in a cluster are presented. In response to determining that a node is no longer part of a sub-cluster, another node in the sub-cluster is designated as a racer node. The racer node accesses a matrix, and the matrix includes information to determine whether a majority of coordination points in a cluster are accessible by nodes in the sub-cluster. Based on the accessing, a determination is made that the information indicates that the majority of coordination points are accessible by the nodes. The information is then broadcasted.

Abstract: Disclosed herein are methods, systems, and processes to perform application aware input/output (I/O) fencing operations. A determination is made that a cluster has been partitioned. The cluster includes multiple nodes. As a result of the partitioning, the nodes are split between a first network partition with a first set of nodes and a second network partition with a second set of nodes. Another determination is made that instances of an application are executing on the first set of nodes and the second set of nodes. An application aware I/O fencing operation is then performed that causes termination of instances of the application executing on the first set of nodes or on the second set of nodes.

Abstract: Disclosed herein are methods, systems, and processes to perform application aware input/output (I/O) fencing operations. A determination is made that an instance of an application is executing on a node that is part of a cluster. In response to the determination that the instance of the application is executing on the node, an identifier that associates the instance of the application and the node on which the instance of the application is executing is generated for the instance of the application. The identifier is installed on one or more coordination points.

Abstract: 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.

Abstract: Disclosed herein are methods, systems, and processes to perform application aware input/output (I/O) fencing operations. A determination is made that an instance of an application is executing on a node that is part of a cluster. In response to the determination that the instance of the application is executing on the node, an identifier that associates the instance of the application and the node on which the instance of the application is executing is generated for the instance of the application. The identifier is installed on one or more coordination points.

Abstract: Disclosed herein are methods, systems, and processes to perform application aware input/output (I/O) fencing operations. A determination is made that a cluster has been partitioned. The cluster includes multiple nodes. As a result of the partitioning, the nodes are split between a first network partition with a first set of nodes and a second network partition with a second set of nodes. Another determination is made that instances of an application are executing on the first set of nodes and the second set of nodes. An application aware I/O fencing operation is then performed that causes termination of instances of the application executing on the first set of nodes or on the second set of nodes.