Abstract: The present disclosure relates to a data storage system, and processes and computer programs for such data storage system, for example including processing of: managing one or more metadata tree structures for storing data to one or more storage devices of the data storage system in units of blocks, each metadata tree structure including a root node pointing directly and/or indirectly to blocks, and a leaf tree level having one or more direct nodes pointing to blocks, and optionally including one or more intermediate tree levels having one or more indirect nodes pointing to indirect nodes and/or direct nodes of the respective metadata tree structure; maintaining the root node and/or nodes of at least one tree level of each of at least one metadata structure in a cache memory; and managing I/O access to data based on the one or more metadata structures, including obtaining the root node and/or nodes of the at least one tree level of the metadata structure maintained in the cache memory from the cache memory an

Abstract: The data storage system includes one or more storage apparatuses and a file system server connected to the one or more storage apparatuses and to one or more host computers. Write operations are controlled by providing a free space object which stores a plurality of indicators, each indicator being associated with one of a plurality of storage units for storing data units in the one or more storage apparatuses and each indicator indicating whether the associated storage unit is free or used, executing a read-ahead examination which comprises examining a set of indicators of the free space object for identifying one or more used storage units associated with indicators of the set, in particular for observing a fragmentation status of the storage units associated with the indicators of the set, and executing an allocation examination which comprises examining one or more indicators.

Abstract: The present disclosure relates to a data storage system, and processes and computer programs for such data storage system, for example including processing of: managing one or more metadata tree structures for storing data to one or more storage devices of the data storage system in units of blocks, each metadata tree structure including a root node pointing directly and/or indirectly to blocks, and a leaf tree level having one or more direct nodes pointing to blocks, and optionally including one or more intermediate tree levels having one or more indirect nodes pointing to indirect nodes and/or direct nodes of the respective metadata tree structure; maintaining the root node and/or nodes of at least one tree level of each of at least one metadata structure in a cache memory; and managing I/O access to data based on the one or more metadata structures, including obtaining the root node and/or nodes of the at least one tree level of the metadata structure maintained in the cache memory from the cache memory an

Abstract: The present disclosure relates to a data storage system, and processes and computer programs for such data storage system, for example including processing of: managing one or more metadata tree structures for storing data to one or more storage devices of the data storage system in units of blocks, each metadata tree structure including a root node pointing directly and/or indirectly to blocks, and a leaf tree level having one or more direct nodes pointing to blocks, and optionally including one or more intermediate tree levels having one or more indirect nodes pointing to indirect nodes and/or direct nodes of the respective metadata tree structure; maintaining the root node and/or nodes of at least one tree level of each of at least one metadata structure in a cache memory; and managing I/O access to data based on the one or more metadata structures.

Abstract: The present disclosure relates to a data storage system, and processes and computer programs for such data storage system, for example including processing of: managing one or more metadata tree structures for storing data to one or more storage devices of the data storage system in units of blocks, each metadata tree structure including a root node pointing directly and/or indirectly to blocks, and a leaf tree level having one or more direct nodes pointing to blocks, and optionally including one or more intermediate tree levels having one or more indirect nodes pointing to indirect nodes and/or direct nodes of the respective metadata tree structure; maintaining the root node and/or nodes of at least one tree level of each of at least one metadata structure in a cache memory; and managing I/O access to data based on the one or more metadata structures.

Abstract: The data storage system includes one or more storage apparatuses and a file system server connected to the one or more storage apparatuses and to one or more host computers. Write operations are controlled by providing a free space object which stores a plurality of indicators, each indicator being associated with one of a plurality of storage units for storing data units in the one or more storage apparatuses and each indicator indicating whether the associated storage unit is free or used, executing a read-ahead examination which comprises examining a set of indicators of the free space object for identifying one or more used storage units associated with indicators of the set, in particular for observing a fragmentation status of the storage units associated with the indicators of the set, and executing an allocation examination which comprises examining one or more indicators.

Abstract: Interface apparatus for connection between a data handling device and a data communication medium to enable data to be transferred between the device and the medium, is constituted, inter alia, by a data alignment device (7, 8) coupled in use to the data handling device. A memory (5, 6) is coupled for data transfer to the data alignment device (7, 8) and includes a number of substantially identical subsidiary, First-In-First-Out (FIFO) memories arranged in parallel. The number of subsidiary memories is chosen such that their overall width is at least equal to the longest length of data to be transferred between the memory (5, 6) and the alignment device (7, 8) in a single transfer step and the width of each subsidiary memory is equal to the shortest length of data to be transferred between the memory and the alignment device in a single transfer step.