Abstract: Provided are a computer program product, system, and method receiving at a cache node notification of changes to files in a source file system served from a cache file system at the cache node. A cache file system is established at the cache node as a local share of a source file system at the source node. The source node establishes a local share of the cache file system at the cache node. Notification is received, from the source node, that the source node modified a source control file for a source file at the source node. In response to receiving the notification, a cache control file, for a cached file in the cache file system, is updated to indicate the source file at the source node is modified. A request is sent to the source node to obtain data for the source file indicated as modified.

Abstract: Provided a computer program product, system, and method for notifying a cache file system of changes to files in a source file system served from the cache file system. The source node establishes a local share of a cache file system at the cache node. The cache file system at the cache node comprises a local share of a source file system at the source node. In response to modifying a source file in the source file system, a source control file for the source file in the local share of the cache file system is updated to indicate the source file is modified. In response to updating the source control file, sending, to the cache node, indication of the updating of the source control file to cause the cache node to update a cache control file to indicate a change to the source file at the source node.

Abstract: Provided a computer program product, system, and method for notifying a cache file system of changes to files in a source file system served from the cache file system. The source node establishes a local share of a cache file system at the cache node. The cache file system at the cache node comprises a local share of a source file system at the source node. In response to modifying a source file in the source file system, a source control file for the source file in the local share of the cache file system is updated to indicate the source file is modified. In response to updating the source control file, sending, to the cache node, indication of the updating of the source control file to cause the cache node to update a cache control file to indicate a change to the source file at the source node.

Abstract: Provided are a computer program product, system, and method receiving at a cache node notification of changes to files in a source file system served from a cache file system at the cache node. A cache file system is established at the cache node as a local share of a source file system at the source node. The source node establishes a local share of the cache file system at the cache node. Notification is received, from the source node, that the source node modified a source control file for a source file at the source node. In response to receiving the notification, a cache control file, for a cached file in the cache file system, is updated to indicate the source file at the source node is modified. A request is sent to the source node to obtain data for the source file indicated as modified.

Abstract: A computer-implemented method according to one embodiment includes, in response to a determination that a predetermined operation has been performed on an object of a first file stored on a first cluster site, storing predetermined information about the object of the first file stored on the first cluster site. The predetermined information is stored on an extended attribute of the first file stored on the first cluster site. In response to a determination that the predetermined operation is performed on an object of a first file stored on a second cluster site, the predetermined information is removed from the extended attribute of the first file stored on the first cluster site. In response to a determination that a failure event has occurred on a queue of the first cluster site, a predetermined recovery process is performed, thereby enabling fulfillment of entries of the queue of the first cluster site.

Abstract: A computer-implemented method according to one embodiment includes initializing a new gateway node at a first site in response to a failure of an old gateway node at the first site; creating, at the new gateway node, a list of dirty directories at the first site; synchronizing, with a second site by a background thread at the first site, all directories within the list of dirty directories; and synchronizing, with the second site by a foreground thread at the first site, new operations performed within the first site after the initialization of the new gateway node.

Abstract: A computer-implemented method according to one embodiment includes receiving, from an application at a metadata node of a clustered computing system, a request for a file, identifying, by the metadata node, a subset of data nodes within the clustered computing system where a portion of the file is stored, determining, by the metadata node, a data node within the subset of data nodes storing the portion of the file in a cache of the data node, and returning to the application, by the metadata node, a location of the portion of the file at the data node storing the portion of the file in the cache of the data node.

Abstract: A computer-implemented method, according to one approach, includes: receiving a data operation request which includes an activated compound operation flag. The data operation request is added to a queue in a gateway node, and the data operation request is eventually transmitted to a disaster recovery site. An inode entry which corresponds to the portion of data is locked, and metadata associated with the inode entry is updated to indicate that the data operation request has been performed at the disaster recovery site. Supplemental data operation requests which correspond to the portion of data are also identified by evaluating the metadata associated with the inode entry. These supplemental data operation requests are transmitted to the disaster recovery site, and the metadata associated with the inode entry is updated to indicate that the supplemental data operation requests have been performed at the disaster recovery site. Furthermore, the inode entry is unlocked.

Abstract: A system identifies (I) a first independent filesystem that (i) includes a file and (ii) uses file-handles to locate files and (II) a second independent filesystem that (i) operates independently of file-handles, associated with the first independent filesystem, when locating files and (ii) includes a copy of the file. The system generates a file-handle for the copy of the file on an inode of first independent filesystem based on a full-path for the copy of the file on the second independent filesystem. The system replicates one or more data blocks between the first independent filesystem and the second independent filesystem based, at least in part, on the full-path.

Abstract: A computer-implemented method according to one embodiment includes initiating a file system interface in a kernel space of a system cluster, capturing a data access request sent from a user space of the system cluster, utilizing the file system interface, where the data access request is sent utilizing one or more protocols of a first file system, and redirecting the data access request to a second file system of the system cluster, utilizing the file system interface.

Abstract: A system identifies (I) a first independent filesystem that (i) includes a file and (ii) uses file-handles to locate files and (II) a second independent filesystem that (i) operates independently of file-handles, associated with the first independent filesystem, when locating files and (ii) includes a copy of the file. The system generates a file-handle for the copy of the file on an inode of first independent filesystem based on a full-path for the copy of the file on the second independent filesystem. The system replicates one or more data blocks between the first independent filesystem and the second independent filesystem based, at least in part, on the full-path.

Abstract: A computer-implemented method according to one embodiment includes receiving, on a first gateway node of a first cluster site, an input/output (I/O) request for a first fileset, and determining a collection of mount operations in which to add the I/O request for the first fileset. The determining includes hashing information of the first fileset against more than one collection of mount operations. The method further includes adding the I/O request for the first fileset to a first determined collection of mount operations, and outputting the first determined collection of mount operations to a first network file system (NFS) server. The first NFS server is one of a plurality of NFS servers of a second cluster site. Moreover, the first NFS server and at least one other NFS server of the plurality of NFS servers are configured to receive a collection of mount operations from the first gateway node.

Abstract: A computer-implemented method according to one embodiment includes receiving, from an application at a metadata node of a clustered computing system, a request for a file, identifying, by the metadata node, a subset of data nodes within the clustered computing system where a portion of the file is stored, determining, by the metadata node, a data node within the subset of data nodes storing the portion of the file in a cache of the data node, and returning to the application, by the metadata node, a location of the portion of the file at the data node storing the portion of the file in the cache of the data node.

Abstract: A computer-implemented method, according to one embodiment, includes: establishing a recovery cluster as an acting primary cluster in response to determining that a primary cluster has gone offline. In response to determining that the primary cluster is back online, the acting primary cluster is synched with the online primary cluster by: capturing a snapshot of the acting primary cluster, and pausing a normal queue of the acting primary cluster. The snapshot of the acting primary cluster is further compared with a most recent snapshot of the online primary cluster, and each difference therebetween is added to a priority queue of the acting primary cluster. Each of the differences in the priority queue are transmitted to the online primary cluster, followed by the entries in the normal queue in response to determining that each of the differences in the priority queue have been transmitted to the online primary cluster.

Abstract: A computer-implemented method, according to one embodiment, includes: receiving, by a computer, a data access request; sending, by the computer, a recall request to a remote storage location for data which corresponds to the data access request; and receiving, by the computer, a copy of an existing object which includes blocks. The data which corresponds to the data access request is stored in at least one of the blocks. The data access request is satisfied, by the computer, by providing the copy of the existing object. Moreover, a sparse object, which only includes ones of the blocks which contain data that has been modified, is received by the computer. The sparse object is sent, by the computer, to the remote storage location; and one or more instructions to use the blocks included in the sparse object to update the existing object are also sent by the computer.

Abstract: A computer-implemented method according to one embodiment includes initiating a file system interface in a kernel space of a system cluster, capturing a data access request sent from a user space of the system cluster, utilizing the file system interface, where the data access request is sent utilizing one or more protocols of a first file system, and redirecting the data access request to a second file system of the system cluster, utilizing the file system interface.