Abstract: Peer-to-peer redundant file server system and methods include clients that determine a target storage provider to contact for a particular storage transaction based on a pathname provided by the filesystem and a predetermined scheme such as a hash function applied to a portion of the pathname. Servers use the same scheme to determine where to store relevant file information so that the clients can locate the file information. The target storage provider may store the file itself and/or may store metadata that identifies one or more other storage providers where the file is stored. A file may be replicated in multiple storage providers, and the metadata may include a list of storage providers from which the clients can select (e.g., randomly) in order to access the file.

Abstract: Peer-to-peer redundant file server system and methods include clients that determine a target storage provider to contact for a particular storage transaction based on a pathname provided by the filesystem and a predetermined scheme such as a hash function applied to a portion of the pathname. Servers use the same scheme to determine where to store relevant file information so that the clients can locate the file information. The target storage provider may store the file itself and/or may store metadata that identifies one or more other storage providers where the file is stored. A file may be replicated in multiple storage providers, and the metadata may include a list of storage providers from which the clients can select (e.g., randomly) in order to access the file.

Abstract: Peer-to-peer redundant file server system and methods include clients that determine a target storage provider to contact for a particular storage transaction based on a pathname provided by the filesystem and a predetermined scheme such as a hash function applied to a portion of the pathname. Servers use the same scheme to determine where to store relevant file information so that the clients can locate the file information. The target storage provider may store the file itself and /or may store metadata that identifies one or more other storage providers where the file is stored. A file may be replicated in multiple storage providers, and the metadata may include a list of storage providers from which the clients can select (e.g., randomly) in order to access the file.

Abstract: Peer-to-peer redundant file server system and methods include clients that determine a target storage provider to contact for a particular storage transaction based on a pathname provided by the filesystem and a predetermined scheme such as a hash function applied to a portion of the pathname. Servers use the same scheme to determine where to store relevant file information so that the clients can locate the file information. The target storage provider may store the file itself and/or may store metadata that identifies one or more other storage providers where the file is stored. A file may be replicated in multiple storage providers, and the metadata may include a list of storage providers from which the clients can select (e.g., randomly) in order to access the file.

Abstract: Peer-to-peer redundant file server system and methods include clients that determine a target storage provider to contact for a particular storage transaction based on a pathname provided by the filesystem and a predetermined scheme such as a hash function applied to a portion of the pathname. Servers use the same scheme to determine where to store relevant file information so that the clients can locate the file information. The target storage provider may store the file itself and/or may store metadata that identifies one or more other storage providers where the file is stored. A file may be replicated in multiple storage providers, and the metadata may include a list of storage providers from which the clients can select (e.g., randomly) in order to access the file.

Abstract: Peer-to-peer redundant file server system and methods include clients that determine a target storage provider to contact for a particular storage transaction based on a pathname provided by the filesystem and a predetermined scheme such as a hash function applied to a portion of the pathname. Servers use the same scheme to determine where to store relevant file information so that the clients can locate the file information. The target storage provider may store the file itself and/or may store metadata that identifies one or more other storage providers where the file is stored. A file may be replicated in multiple storage providers, and the metadata may include a list of storage providers from which the clients can select (e.g., randomly) in order to access the file.

Abstract: Peer-to-peer redundant file server system and methods include clients that determine a target storage provider to contact for a particular storage transaction based on a pathname provided by the filesystem and a predetermined scheme such as a hash function applied to a portion of the pathname. Servers use the same scheme to determine where to store relevant file information so that the clients can locate the file information. The target storage provider may store the file itself and/or may store metadata that identifies one or more other storage providers where the file is stored. A file may be replicated in multiple storage providers, and the metadata may include a list of storage providers from which the clients can select (e.g., randomly) in order to access the file.

Abstract: In an aggregated file system, a method of processing a user file retrieves user file metadata and user data from a metadata server and applies operations to the user data in accordance with a file open request from a client. At the end of the process, the method stores the processed user data at a location in accordance with a predefined rule and updates the metadata in the metadata server to reference the processed user data at the location. In some embodiments, the predefined rule is to choose a location between the metadata server and a separate storage server in accordance with the size of the processed user data. If the size is still smaller than a predetermined threshold, the user data is stored in the metadata server. Otherwise, the user data is stored in the storage server.

Abstract: In a switched file system, a file switching device is logically positioned between clients and file servers and communicates with the clients and the file servers using standard network file protocols. The file switching device appears as a server to the client devices and as a client to the file servers. The file switching device aggregates storage from multiple file servers into a global filesystem and presents a global namespace to the client devices. The file switching device typically supports a “native” mode for integrating legacy files into the global namespace and an “extended” mode for actively managing files across one or more file servers. Typically, native-mode files may be accessed directly or indirectly via the file switching device, while extended-mode files may be accessed only through the file switching device. The file switching device may manage file storage using various types of rules, e.g., for managing multiple storage tiers or for applying different types of encoding schemes to files.

Abstract: A distributed file system and method distributes file system objects across multiple self-contained volumes, where each volume is owned by a unique file system node. Logical links are used to reference a file system object between volumes. Each file system node includes a relocation directory in which is maintained hard links to locally-stored file system objects that are referenced from another file system node using logical links. Various file system operations that involve multiple volumes are performed without having to place a write lock on more than one volume at a time. Various caching schemes allow the various file system nodes to cache file system object data and metadata.

Abstract: A distributed file system and method distributes file system objects across multiple self-contained volumes, where each volume is owned by a unique file system node. Logical links are used to reference a file system object between volumes. Each file system node includes a relocation directory in which is maintained hard links to locally-stored file system objects that are referenced from another file system node using logical links. Various file system operations that involve multiple volumes are performed without having to place a write lock on more than one volume at a time. Various caching schemes allow the various file system nodes to cache file system object data and metadata.

Abstract: In an aggregated file system, metadata is partitioned into multiple metadata volumes. On receipt of a file processing request, a file switch examines its mount entry cache to identify a target metadata volume that hosts the metadata of the requested file. The identification begins with mount entries at a root volume and continues recursively by examining a portion of the absolute pathname of the file until the target metadata volume is identified. Finally, the file switch forwards the request to a metadata server managing the target metadata volume. Since the identification process is carried out completely within the file switch, there is no need for multiple expensive network accesses to different metadata servers.

Abstract: In an aggregated file system, metadata is partitioned into multiple metadata volumes. On receipt of a file processing request, a file switch examines its mount entry cache to identify a target metadata volume that hosts the metadata of the requested file. The identification begins with mount entries at a root volume and continues recursively by examining a portion of the absolute pathname of the file until the target metadata volume is identified. Finally, the file switch forwards the request to a metadata server managing the target metadata volume. Since the identification process is carried out completely within the file switch, there is no need for multiple expensive network accesses to different metadata servers.

Abstract: Peer-to-peer redundant file server system and methods include clients that determine a target storage provider to contact for a particular storage transaction based on a pathname provided by the filesystem and a predetermined scheme such as a hash function applied to a portion of the pathname. Servers use the same scheme to determine where to store relevant file information so that the clients can locate the file information. The target storage provider may store the file itself and/or may store metadata that identifies one or more other storage providers where the file is stored. A file may be replicated in multiple storage providers, and the metadata may include a list of storage providers from which the clients can select (e.g., randomly) in order to access the file.

Abstract: In a switched file system, a file switching device is logically positioned between clients and file servers and communicates with the clients and the file servers using standard network file protocols. The file switching device appears as a server to the client devices and as a client to the file servers. The file switching device aggregates storage from multiple file servers into a global filesystem and presents a global namespace to the client devices. The file switching device typically supports a “native” mode for integrating legacy files into the global namespace and an “extended” mode for actively managing files across one or more file servers. Typically, native-mode files may be accessed directly or indirectly via the file switching device, while extended-mode files may be accessed only through the file switching device. The file switching device may manage file storage using various types of rules, e.g., for managing multiple storage tiers or for applying different types of encoding schemes to files.

Abstract: In a switched file system, a file switching device is logically positioned between clients and file servers and communicates with the clients and the file servers using standard network file protocols. The file switching device appears as a server to the client devices and as a client to the file servers. The file switching device aggregates storage from multiple file servers into a global filesystem and presents a global namespace to the client devices. The file switching device typically supports a “native” mode for integrating legacy files into the global namespace and an “extended” mode for actively managing files across one or more file servers. Typically, native-mode files may be accessed directly or indirectly via the file switching device, while extended-mode files may be accessed only through the file switching device. The file switching device may manage file storage using various types of rules, e.g., for managing multiple storage tiers or for applying different types of encoding schemes to files.

Abstract: In an aggregated file system, a method of processing a user file retrieves its metadata and user data from a metadata server and applies operations to the user data in accordance with a file open request from a client. At the end of the process, the method stores the processed user data at a location in accordance with a predefined rule and updates the metadata in the metadata server to reference the processed user data at the location. In some embodiments, the predefined rule is to choose a location between the metadata server and a separate storage server in accordance with the size of the processed user data. If the size is still smaller than a predetermined threshold, the user data is stored in the metadata server. Otherwise, the user data is stored in the storage server.

Abstract: In an aggregated file system, a file may begin with a set of stripe fragments all in the RAID-5 scheme in order to take advantage of the RAID-5 scheme's storage efficiency. After that, when one of the fragments is accessed by a file switch, it will be duplicated into the data mirroring scheme. The file's corresponding metadata server maintains a data structure, e.g., a bitmap, indicating which fragments have been duplicated into the data mirroring scheme. In other words, the file, at this moment, exists in a hybrid scheme. A file consolidator running on the metadata server is triggered at a predefined time to copy the fragments from the data mirroring scheme back to the RAID-5 scheme, This file consolidator also updates the bitmap to reflect the changes to the file's scheme change. This hybrid scheme is expected to increase the I/O capacity of the conventional RAID-5 scheme and the storage usage of the conventional mirroring scheme.

Abstract: In an aggregated file system, metadata is partitioned into multiple metadata volumes. On receipt of a file processing request, a file switch examines its mount entry cache to identify a target metadata volume that hosts the metadata of the requested file. The identification begins with mount entries at a root volume and continues recursively by examining a portion of the absolute pathname of the file until the target metadata volume is identified. Finally, the file switch forwards the request to a metadata server managing the target metadata volume. Since the identification process is carried out completely within the file switch, there is no need for multiple expensive network accesses to different metadata servers.