Abstract: Embodiments include a method for fault tolerance in the delivery of event information within a file system cluster. One or more processors to determine event information associated with file system activity performed by a node of the cluster. The one or more processors add the event information to an event log buffer in memory. The one or more processors receive a first log sequence number (LSN) associated with flushing of recovery information from a recovery log buffer. The one or more processors determine the event information in the event log buffer having a log sequence number less than or equal to the first log sequence number, and determining the event information includes log sequence numbers less than or equal to the first log sequence number, the one or more processors flush the corresponding event information from the event log buffer to disk storage.

Abstract: Embodiments include a method for fault tolerance in the delivery of event information within a file system cluster. One or more processors to determine event information associated with file system activity performed by a node of the cluster. The one or more processors add the event information to an event log buffer in memory. The one or more processors receive a first log sequence number (LSN) associated with flushing of recovery information from a recovery log buffer. The one or more processors determine the event information in the event log buffer having a log sequence number less than or equal to the first log sequence number, and determining the event information includes log sequence numbers less than or equal to the first log sequence number, the one or more processors flush the corresponding event information from the event log buffer to disk storage.

Abstract: Methods and systems for an enhanced restripe mechanism are provided. A system for an enhanced restriping mechanism includes a data storage module that stripes data across a plurality of storage devices, wherein the plurality of storage devices are arranged into a plurality of storage pools and the data is distributed across the plurality of storage pools. Also, the system may include a movement detection module that detects changes in the arrangement of the plurality of storage devices that would cause the data on a storage device in the plurality of storage devices to be moved onto other storage devices in the plurality of storage devices. Further, the system may include a restriping module that restripes disk data from the storage device in the plurality of storage devices onto the other storage devices in response to the detected change based on access characteristics of the data.

Abstract: Methods and systems for an enhanced restripe mechanism are provided. A system for an enhanced restriping mechanism includes a data storage module that stripes data across a plurality of storage devices, wherein the plurality of storage devices are arranged into a plurality of storage pools and the data is distributed across the plurality of storage pools. Also, the system may include a movement detection module that detects changes in the arrangement of the plurality of storage devices that would cause the data on a storage device in the plurality of storage devices to be moved onto other storage devices in the plurality of storage devices. Further, the system may include a restriping module that restripes disk data from the storage device in the plurality of storage devices onto the other storage devices in response to the detected change based on access characteristics of the data.

Abstract: Methods and systems for an enhanced restripe mechanism are provided. A system for an enhanced restriping mechanism includes a data storage module that stripes data across a plurality of storage devices, wherein the plurality of storage devices are arranged into a plurality of storage pools and the data is distributed across the plurality of storage pools. Also, the system may include a movement detection module that detects changes in the arrangement of the plurality of storage devices that would cause the data on a storage device in the plurality of storage devices to be moved onto other storage devices in the plurality of storage devices. Further, the system may include a restriping module that restripes disk data from the storage device in the plurality of storage devices onto the other storage devices in response to the detected change based on access characteristics of the data.

Abstract: A computer includes a storage segment fully allocated to an application. The storage segment initially includes a repeating initialization data pattern there within. After the application begins its workload, the application writes application data to a portion of the storage segment. A snapshot application takes a snapshot of the storage segment. After the snapshot, the application generates a post-snapshot-write to the storage segment. The snapshot application determines whether the post-snapshot-write modifies application data or modifies the repeating initialization data pattern. If the post-snapshot-write modifies the repeating initialization data pattern within the storage segment, the snapshot application blocks the repeating initialization data pattern from being copied and moved which resultantly blocks modification of the snapshot.

Abstract: Technology for accessing previous versions of data objects within a storage cluster including multiple storage volumes under a common namespace is disclosed herein. In some embodiments, the network storage cluster having multiple cooperative storage nodes receives a namespace identifier for a previous version of a data object. The namespace identifier includes a namespace path containing a volume junction and a time indicator indicating a point in time when the previous version of the data object existed. The network storage cluster identifies a storage volume within the network storage cluster using the volume junction. The volume junction points to a root directory of a file system of the storage volume. The network storage cluster locates, based on the namespace path, the previous version of the data object within a snapshot copy of the storage volume, wherein the snapshot copy is identified by the time indicator.

Abstract: Embodiments described herein provide a technique for securely responding to an enumeration request of a data container stored at a location referenced by a junction or mount point within a share served by a storage system. To that end, the technique applies access permissions of the data container at the referenced location instead of permissions that may reside at the junction or mount point. Upon determining that the permissions are insufficient to allow access to the data container, the technique ensures that a descriptor of the junction or mount point is not included in a response to the enumeration request.

Abstract: Embodiments described herein provide a technique for securely responding to an enumeration request of a data container stored at a location referenced by a junction or mount point within a share served by a storage system. To that end, the technique applies access permissions of the data container at the referenced location instead of permissions that may reside at the junction or mount point. Upon determining that the permissions are insufficient to allow access to the data container, the technique ensures that a descriptor of the junction or mount point is not included in a response to the enumeration request.

Abstract: Method and system for access based directory enumeration is provided. When a directory is enumerated for a first time, user credentials are verified against an access control list (ACL) entry that is referenced by an ACL inode (referred to as Xnode). The Xnode number is obtained from a file handle for a directory entry. The verification is recorded in a data structure that stores the Xnode identifier and user identifier. When the directory is enumerated again, the data structure is used to verify that the user has been validated before, instead of loading and checking against an ACL entry.

Abstract: Technology for accessing previous versions of data objects within a storage cluster including multiple storage volumes under a common namespace is disclosed herein. In some embodiments, the network storage cluster having multiple cooperative storage nodes receives a namespace identifier for a previous version of a data object. The namespace identifier includes a namespace path containing a volume junction and a time indicator indicating a point in time when the previous version of the data object existed. The network storage cluster identifies a storage volume within the network storage cluster using the volume junction. The volume junction points to a root directory of a file system of the storage volume. The network storage cluster locates, based on the namespace path, the previous version of the data object within a snapshot copy of the storage volume, wherein the snapshot copy is identified by the time indicator.

Abstract: Provided is a method and system for reliably multicasting a data transmission from a server to one or more clients, which may be connected via a control channel and a multicast data channel. In one example, the method includes sending a first data transmission to the clients over the multicast data channel. A response is received over the control channel from at least some of the clients. The response identifies data not received by the responding client. In some examples, the response may indicate that all the data was received. The server determines a minimum retransmission data set based on the responses. The minimum retransmission data set includes at least some of the data not received by the client during the first data transmission. The minimum retransmission data set is sent over the multicast data channel and received by the clients that did not receive it during the first data transmission.

Abstract: A system and method for prefetching one or more embedded objects marked uncacheable using a buffer on a prefetch cache to temporarily store the uncacheable object. The buffer is allocated to a socket that is established between the prefetch cache and a server subsequent to the establishment of an initial connection. A prefetch caching process retrieves one or more embedded objects from the server using the socket based on the preconfigured set of rules. The prefetch caching process determines whether the embedded object is uncacheable, and if so loads the object into the buffer. The prefetch caching process waits a predetermined time period for client request for the object. If the request is received prior to expiration of the time period, the prefetch caching process sends the object to the client. Otherwise, the process “flushes” the buffer, thereby discarding the object, and then closes the socket.

Abstract: Provided is a method and system for reliably multicasting a data transmission from a server to one or more clients, which may be connected via a control channel and a multicast data channel. In one example, the method includes sending a first data transmission to the clients over the multicast data channel. A response is received over the control channel from at least some of the clients. The response identifies data not received by the responding client. In some examples, the response may indicate that all the data was received. The server determines a minimum retransmission data set based on the responses. The minimum retransmission data set includes at least some of the data not received by the client during the first data transmission. The minimum retransmission data set is sent over the multicast data channel and received by the clients that did not receive it during the first data transmission.

Abstract: Provided is a method and system for reliably multicasting a data transmission from a server to one or more clients, which may be connected via a control channel and a multicast data channel. In one example, the method includes sending a first data transmission to the clients over the multicast data channel. A response is received over the control channel from at least some of the clients. The response identifies data not received by the responding client. In some examples, the response may indicate that all the data was received. The server determines a minimum retransmission data set based on the responses. The minimum retransmission data set includes at least some of the data not received by the client during the first data transmission. The minimum retransmission data set is sent over the multicast data channel and received by the clients that did not receive it during the first data transmission.

Abstract: A system and method for prefetching one or more embedded objects marked uncacheable using a staging area on a prefetch cache to temporarily store (load) the uncacheable object. The staging area is a buffer allocated to a socket that is established between a prefetch cache and the server subsequent to the establishment of an initial connection. A prefetch caching process retrieves one or more embedded objects from the server using one or more sockets 145 based on the response sent to the client and a preconfigured set of rules. Additionally, the prefetch caching process determines whether the embedded object is uncacheable. The prefetch caching process then loads the object into the buffer associated with the socket. The prefetch caching process waits a predetermined time period for the cache to receive a client request for the object. If the request is received prior to expiration of the time period, the prefetch caching process sends the object over the socket.