Sun Microsystems, Inc.

Emc Corporation

Thomas J Dwyer, Iii

Sairam Veeraswamy

Ravi Wijayaratne

David Noveck

Daniel Alan Muntz

Charles D Kunzman

Described are techniques for performing quota management in a distributed file system. An allocation quota specifies an upper limit of storage for allocation for a quota set of the distributed file system. The distributed file system includes metadata file system(s) and data file system(s). For files in the distributed file system, metadata is stored in one of the metadata file systems and file content data is stored in the data file systems. A quota coordinator partitions the allocation quota among the data file systems. The data file systems are allocators of storage and each receives a portion of the allocation quota specifying an upper limit of storage that the data file system has available for allocation for the quota set. Storage is allocated for client requests. The storage allocation is performed by each of the data file systems in accordance with the portion of the allocation quota assigned.

Providing file system quota support for a file system having separated data and metadata

Providing file sytem quota support for a file system having separated data and metadata

One embodiment of the present invention provides a system that facilitates atomically updating selected bits within a register in a computing system. During operation, the system receives a command to update selected bits within the register. This command includes a data word and a control bit pattern. Next, the system examines the control bit pattern to determine an operation to be performed on the register. The system then performs the operation, which involves using the dataword to modify a content of the register atomically, without blocking subsequent commands to update the register.

Method and apparatus for atomically changing selected bits within a register

A method implemented in a computer system for storing non-volatile configuration information (NVCI), wherein NVCI is stored in one or more active segments of a segmented flash memory. The NVCI consists of a series of key-value pairs. When the computer system is started, the key-value pairs are read from the active segment, beginning with the least recently stored and ending with the most recently stored. The key-value pairs are inserted into a hash table, with later-read key-value pairs replacing earlier-read key-value pairs of the same key. Write accesses to the NVCI are made to both the hash table and the active segment of flash memory. When an active segment of the flash memory is filled to a threshold capacity, current key-value pairs stored in the hash table are written to a new flash memory segment, which then becomes the active segment.

Method and apparatus for storing non-volatile configuration information

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Sunnyvale, CA, United States of America

Thomas J Dwyer, Iii