Abstract: A method and system for allocating blocks of disk in persistent storage to requesting threads. A primary data structure is provided for organizing and categorizing blocks of disk space. In addition, a secondary data structure is provided for maintaining a list of all active file system processes and blocks of disk space used by those processes. Blocks of disk space are assigned to pages. At such time as a thread may request allocation of disk space, both data structures are reviewed to determine if the requested disk space is available and to limit access of available disk space to a single page of memory to a single thread at any one time.

Abstract: Improved techniques are disclosed for accessing content in file systems, allowing file system clients to realize advantages of file system referrals even though a file access protocol used by the client is not specifically adapted for referral objects. (For example, the client may have a legacy file system protocol or a proprietary file system protocol which does not support referrals.) These advantages include a uniform name space view of content in a network file system, and an ability to locate content in a (nearly) seamless and transparent manner, even though the content may be dynamically moved from one location to another or replicated in different locations. A file system server returns a symbolic link in place of a referral, and an automated file mounting process on the client is leveraged to access the content using the link. Built-in crash recovery techniques of the file system client are leveraged to access moved content.

Abstract: A method and system for allocating blocks of disk in persistent storage to requesting threads. A primary data structure is provided for organizing and categorizing blocks of disk space. In addition, a secondary data structure is provided for maintaining a list of all active file system processes and blocks of disk space used by those processes. Blocks of disk space are assigned to pages. At such time as a thread may request allocation of disk space, both data structures are reviewed to determine if the requested disk space is available and to limit access of available disk space to a single page of memory to a single thread at any one time.

Abstract: A method and system for allocating blocks of disk in persistent storage to requesting threads. A primary data structure is provided for organizing and categorizing blocks of disk space. In addition, a secondary data structure is provided for maintaining a list of all active file system processes and blocks of disk space used by those processes. Blocks of disk space are assigned to pages. At such time as a thread may request allocation of disk space, both data structures are reviewed to determine if the requested disk space is available and to limit access of available disk space to a single page of memory to a single thread at any one time.

Abstract: In a cluster of computing nodes having shared access to one or more volumes of data storage using a parallel file system, a method for managing the data storage includes initiating a data management application in the cluster using a data management application programming interface (DMAPI) of the parallel file system. When a request submitted to the parallel file system is received on one of the nodes to perform an operation on a file in one of the volumes of data storage, a data management access right is obtained from the DMAPI responsive to the request The operation is performed on the file using the access right.

Abstract: In one form, in a method for mapping file handles, protocol data elements are created for respective file system protocols. Such a protocol data element identifies a structure of server handles for the data element's corresponding protocol. File system data elements are created for server file systems. Such a file system data element includes a file system identification (FSID) attribute. Responsive to accessing an object of one of the server file systems, a value for the FSID attribute of the corresponding file system data element is created for reconstructing the object's server handle. Creating the value includes parsing, responsive to one of the protocol data elements, an FSID of a server handle for the object.

Abstract: A system provides referencing from one file system server to another through the use of a file system location database improving movement and replication of file systems. When a file system is moved from a first file system server a data object that references the file system remains in the first server and contains information used to find the current location of the file system. The actual location of the file system is stored in the separate file system location database which contains the locations of file systems on a number of file system servers. This allows the data in a file system to be replicated or moved without requiring updates to the data in any redirecting or referencing servers.

Abstract: A method and system for allocating blocks of disk in persistent storage to requesting threads. A primary data structure is provided for organizing and categorizing blocks of disk space. In addition, a secondary data structure is provided for maintaining a list of all active file system processes and blocks of disk space used by those processes. Blocks of disk space are assigned to pages. At such time as a thread may request allocation of disk space, both data structures are reviewed to determine if the requested disk space is available and to limit access of available disk space to a single page of memory to a single thread at any one time.

Abstract: Improved techniques are disclosed for accessing content in file systems, allowing file system clients to realize advantages of file system referrals even though a file access protocol used by the client is not specifically adapted for referral objects. (For example, the client may have a legacy file system protocol or a proprietary file system protocol which does not support referrals.) These advantages include a uniform name space view of content in a network file system, and an ability to locate content in a (nearly) seamless and transparent manner, even though the content may be dynamically moved from one location to another or replicated in different locations. A file system server returns a symbolic link in place of a referral, and an automated file mounting process on the client is leveraged to access the content using the link. Built-in crash recovery techniques of the file system client are leveraged to access moved content.

Abstract: A system provides referencing from one file system server to another through the use of a file system location database, improving movement and replication of file systems. When a file system is moved from a first file system server, a data object that references the file system remains in the first server and contains information used to find the current location of the file system. The actual location of the file system is stored in the separate file system location database, which contains the locations of file systems on a number of file system servers. This allows the data in a file system to be replicated or moved without requiring updates to the data in any redirecting or referencing servers.

Abstract: Improved techniques are disclosed for accessing content in file systems, allowing file system clients to realize advantages of file system referrals even though a file access protocol used by the client is not specifically adapted for referral objects. (For example, the client may have a legacy file system protocol or a proprietary file system protocol which does not support referrals.) These advantages include a uniform name space view of content in a network file system, and an ability to locate content in a (nearly) seamless and transparent manner, even though the content may be dynamically moved from one location to another or replicated in different locations. A file system server returns a symbolic link in place of a referral, and an automated file mounting process on the client is leveraged to access the content using the link. Built-in crash recovery techniques of the file system client are leveraged to access moved content.

Abstract: In one form, in a method for making file systems accessible, a referring file system attribute is created, responsive to a first file system having a referral object referring to a second file system. The referring file system attribute describes referring file system identification for the first file system. A path attribute is created, responsive to the first file system having the referral object, describing a path from a root of the first file system to the referral object. A referred file system attribute is created, responsive to the first file system having the referral object, describing a referred file system identification for the second file system. A parent attribute is created, responsive to the first file system having the referral object, describing a parent flag for the second file system.

Abstract: Improved techniques are disclosed for accessing content in file systems, allowing file system clients to realize advantages of file system referrals even though a file access protocol used by the client is not specifically adapted for referral objects. (For example, the client may have a legacy file system protocol or a proprietary file system protocol which does not support referrals.) These advantages include a uniform name space view of content in a network file system, and an ability to locate content in a (nearly) seamless and transparent manner, even though the content may be dynamically moved from one location to another or replicated in different locations. A file system server returns a symbolic link in place of a referral, and an automated file mounting process on the client is leveraged to access the content using the link. Built-in crash recovery techniques of the file system client are leveraged to access moved content.

Abstract: A technique for asynchronous computer disk cache management reduces the burstiness of disk I/O. It provides a periodic sync process to flush modified buffers, wherein only buffers exceeding a threshold age are selected to be flushed. In one variant the sync process only executes when the number of modified buffers in the cache exceeds a threshold, which can be dynamically adapted to changing patterns of cache usage. The age of the dirty buffers is measured by sync periods to minimize time computation. In some embodiments an additional cleaning process flushes old buffers between sync invocations.

Abstract: In one form, in a method for mapping file handles, protocol data elements are created for respective file system protocols. Such a protocol data element identifies a structure of server handles for the data element's corresponding protocol. File system data elements are created for server file systems. Such a file system data element includes a file system identification (FSID) attribute. Responsive to accessing an object of one of the server file systems, a value for the FSID attribute of the corresponding file system data element is created for reconstructing the object's server handle. Creating the value includes parsing, responsive to one of the protocol data elements, an FSID of a server handle for the object.

Abstract: In one form, in a method for making file systems accessible, a referring file system attribute is created, responsive to a first file system having a referral object referring to a second file system. The referring file system attribute describes referring file system identification for the first file system. A path attribute is created, responsive to the first file system having the referral object, describing a path from a root of the first file system to the referral object. A referred file system attribute is created, responsive to the first file system having the referral object, describing a referred file system identification for the second file system. A parent attribute is created, responsive to the first file system having the referral object, describing a parent flag for the second file system.

Abstract: A first file system includes a data object that references a second file system. The data object can be a new or existing file type with data identifying the second file system or some of its properties. The data required to locate the second file system is stored in a file system location data structure that may be located outside the first file system. The data object may then contain a key value, such as a name or a number, identifying the second file system, that can be used to look up the file system location. A referencing server may encode the file system identification and include the encoded file system identification rather than a path. When a server receives a request with a path that is encoded, the server decodes the file system identification. Then, the server may locate the root of the file system identified by the file system identification and return the root object to the client.

Abstract: In a cluster of computing nodes having shared access to one or more file systems in data storage using parallel file system software, a method for managing the data storage includes initiating a session of a data management application on a first one of the nodes, while running a user application on a second one of the nodes. A request is submitted to the parallel file system software by the user application on the second node to mount one of the file systems in the data storage. A mount event message is sent from the second node to the first node responsive to the request, for processing by the data management application on the first node. When the file system is to be unmounted, preunmount and unmount events are sent for processing by the data management application on the first node.

Abstract: In a cluster of computing nodes having shared access to one or more volumes of data storage using a parallel file system, a method for managing the data storage includes initiating a session of a data management application on a session node selected from among the nodes in the cluster. The session node receives an event message in a session queue for processing by the data management application, responsive to a request submitted to the parallel file system by a source node among the nodes in the cluster to perform a file operation on a file in the data storage. Following a failure at the session node, the session queue is reconstructed so that processing of the event message by the data management application can continue after recovery from the failure, and the request can be fulfilled at the source node.

Abstract: In a cluster of computing nodes having shared access to one or more volumes of data storage using a parallel file system, a method for managing the data storage includes initiating a data management application in the cluster using a data management application programming interface (DMAPI) of the parallel file system. When a request submitted to the parallel file system is received on one of the nodes to perform an operation on a file in one of the volumes of data storage, a data management access right is obtained from the DMAPI responsive to the request The operation is performed on the file using the access right.