Abstract: Disclosed herein are methods, systems, and processes to provide coherency across disjoint caches in clustered environments. It is determined whether a data object is owned by an owner node, where the owner node is one of multiple nodes of a cluster. If the owner node for the data object is identified by the determining, a request is sent to the owner node for the data object. However, if the owner node for the data object is not identified by the determining, selects a node in the cluster is selected as the owner node, and the request for the data object is sent to the owner node.

Abstract: The disclosed computer-implemented method for write-once-read-many storage may include (1) receiving, at a file system on the computing device, a request to assign a write-once-read-many (WORM) attribute to a file, wherein the request is received from an application, (2) setting, in response to the request to assign the WORM attribute to the file, a WORM flag in an extended attribute associated with the file, and (3) associating with the file, in response to the setting of the WORM flag, a retention period attribute and read-only access until the end of the retention period. The provided systems and methods may provide per-file WORM support at a file system level using extended attributes of the file system. Various other methods, systems, and computer-readable media are also disclosed.

Abstract: Various systems and methods are provided for using various in-core and on-disk data structures to improve the file creation process through the use of previously-occupied inodes. For example, one method involves updating an in-core data structure in response to receiving a command to delete a first file, such that a first node is assigned to the first file, the in-core data structure is stored in a non-persistent computer-readable storage medium, the in-core data structure comprises a plurality of entries, each of the entries comprises information identifying a respective inode of a plurality of inodes as being available, and the updating the in-core data structure comprises storing information regarding the first inode in a first entry of the plurality of entries; and creating a second file, where the creating comprises assigning the first inode to the second file using the information regarding the first inode stored in the first entry.

Abstract: A system and method is disclosed for optimizing supply chain planning problems associated with a supply chain network. The system includes a supply chain planner coupled with one or more supply chain entities. The supply chain planner determines a supply chain plan for managing the flow of one or more items through the supply chain network.

Abstract: 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 “P” is a sum of “M” data portions and “N” parity portions, (2) creating “K” erasure-coded volumes, where each volume includes one portion on different DSDs, “M” data portions, and “N” parity portions, and (3) combining the “K” volumes to create a file system. Various other methods, systems, and computer-readable media are also disclosed.

Abstract: Various systems, methods and apparatuses for coordinating the sharing of cache data between cluster nodes operating on the same data objects. One embodiment involves a first node in a cluster receiving a request for a data object, querying a global lock manager to determine if a second node in the cluster is the lock owner of the data object, receiving an indication identifying the second node as the lock owner and indicating that the data object is available in the second node's local cache, requesting the data object from the second node, and then receiving the data object from the second node's local cache. Other embodiments include determining whether the lock is a shared lock or an exclusive lock, and either pulling the data object from the local node of the second cache or receiving the data object that is pushed from the second node, as appropriate.

Abstract: Disclosed herein are methods, systems, and processes to track access patterns of inodes, and to issue read-ahead instructions to pre-fetch inodes into memory. A location of a unit of metadata in a metadata storage area is determined. Another location in the metadata storage area that corresponds to a current metadata read operation is determined. Whether a metadata read-ahead operation can be performed is determined using the location of the unit of metadata and the another location. In response to a determination that the metadata read-ahead operation can be performed, the metadata-ahead operation is issued.

Abstract: The disclosed computer-implemented method for maintaining cache coherency may include (1) receiving an indication of a revocation of a grant to an owner node of a shared lock for a data object owned by the owner node; (2) invalidating, in response to the indication of the revocation, a copy of the object in a local cache of the owner node; (3) receiving, while the requesting node holds a grant of an exclusive lock, a request from the requesting node to update the object in the local cache; (4) transmitting, in response to the request to update the object, a request for a shared lock for the object; (5) receiving an indication of a grant of the shared lock; and (6) updating, in response to the grant of the shared lock, the object in the local cache. Various other methods, systems, and computer-readable media are also disclosed.

Abstract: 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.

Abstract: A system and method is disclosed for optimizing supply chain planning problems associated with a supply chain network. The system includes a supply chain planner coupled with one or more supply chain entities. The supply chain planner determines a supply chain plan for managing the flow of one or more items through the supply chain network.

Abstract: The disclosed computer-implemented method for managing delayed allocation on clustered file systems may include (i) receiving, at a global lock manager that stores storage disk allocation information for a plurality of nodes in a clustered file system, a lock request from a node that requests a lock range on a storage disk to store data from a file, (ii) reserving, by the global lock manager, the lock range, (iii) receiving, at the global lock manager, from an additional node, an additional lock request for an additional lock range to store additional data from the file, and (iv) reserving, by the global lock manager, the additional lock range to be adjacent to the lock range on the storage disk based on the additional data on the additional node being from the same file as the data on the node. Various other methods, systems, and computer-readable media are also disclosed.

Abstract: Disclosed herein are methods, systems, and processes track access patterns of inodes, and to issue read-ahead instructions to pre-fetch inodes into memory. An inode is accessed and a directory of the inode is determined. Also determined is whether an entry for the directory exists in a global inode list. If the entry exists in the global inode list, whether a file structure of the directory is sequential or non-sequential is determined. If the entry does not exist in the global inode list, a new entry for the directory is added in the global inode list.

Abstract: A system and method is disclosed for optimizing supply chain planning problems associated with a supply chain network. The system includes a supply chain planner coupled with one or more supply chain entities. The supply chain planner determines a supply chain plan for managing the flow of one or more items through the supply chain network.

Abstract: Improved techniques and systems are disclosed for ensuring that physical storage is available for cached allocating writes in a thinly provisioned storage environment. By monitoring the size of the cached allocating writes in the file system cache and taking cache occupancy reduction actions when criteria for cache reduction are fulfilled, caching of allocating writes that do not have a corresponding physical storage allocation can be eliminated or reduced to a user-configurable maximum without disabling caching of allocating writes. Using these techniques, allocating writes may be cached without risk of data loss.

Abstract: Disclosed herein are methods, systems, and processes to track access patterns of inodes, and to issue read-ahead instructions to pre-fetch inodes into memory. A location of a unit of metadata in a metadata storage area is determined. Another location in the metadata storage area that corresponds to a current metadata read operation is determined. Whether a metadata read-ahead operation can be performed is determined using the location of the unit of metadata and the another location. In response to a determination that the metadata read-ahead operation can be performed, the metadata-ahead operation is issued.

Abstract: Disclosed herein are methods, systems, and processes track access patterns of inodes, and to issue read-ahead instructions to pre-fetch inodes into memory. An inode is accessed and a directory of the inode is determined. Also determined is whether an entry for the directory exists in a global inode list. If the entry exists in the global inode list, whether a file structure of the directory is sequential or non-sequential is determined. If the entry does not exist in the global inode list, a new entry for the directory is added in the global inode list.

Abstract: Various methods and systems for optimizing cache consistency are disclosed. For example, one method involves writing data to a file during a write transaction. The file is stored in a persistent storage device and cached in a non-volatile storage device. The method determines if an in-memory flag associated with the persistent storage device set. If the in-memory flag is not set, the method increases a generation count associated with the persistent storage device before a write transaction is performed on the file. The method then sets the in-memory flag before performing the write transaction on the file. In other examples, the method involves using a persistent flag associated with the non-volatile storage device to maintain cache consistency during a data freeze related to the taking of a snapshot by synchronizing generation counts associated with the persistent storage device and the non-volatile storage device.

Abstract: Various systems and methods for partitioning a directory while allowing concurrent access to the directory. For example, a method involves receiving a request to partition an original directory that comprises a plurality of entries and creating a partitioned directory in response to receiving the request. The method also involves distributing the entries from the original directory to the partitioned directory. Distributing the entries involves sequentially copying each entry from the original directory to the partitioned directory. The method also involves performing an operation on the original directory while the entries are being distributed. Performing the operation involves accessing and/or updating the original directory.

Abstract: Various computer-implemented methods for selective defragmentation are disclosed. In one example, an exemplary method for performing such a task may include: 1) identifying a file system, 2) tracking changes to files in the file system, 3) creating a list of changed files, and then 4) selectively defragmenting files in the list of changed files. Various other methods, systems, and computer-readable media are also disclosed.

Abstract: 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.