Hitachi Data Systems Engineering UK Limited

Hitachi Vantara Corporation

Bluearc UK Limited

Mark Stephen Laker

Christopher J Aston

Trevor Edward Willis

Neil Berrington

Carlo F Garbagnati

Shmuel Shottan

Martin A Dorey

Trevor E Willis

In one aspect, the invention is directed to a method of expanding storage for filesystems in a fine-grained, scalable manner. The method includes determining, by a file server, a run bias for a span, wherein the run bias indicates a number of contiguous chunks of memory associated with an entry in an address translation table for a filesystem. The method includes receiving, by the file server, a request for an expansion of memory for the filesystem. The method includes scoring, by the chunk allocator, each stripe set in a group of stripe sets based at least in part on a number of unused chunks on the stripeset and a number of chunks on the stripeset being used by the filesystem. The method includes allocating, by the chunk allocator, a chunk on the stripeset with the highest score, wherein the allocated chunk lies outside of runs reserved for other filesystems.

Method and apparatus to enable finer-grained, scalable allocation of storage in a data storage system

Available storage locations are identified by searching through a free blocks object non-sequentially. The free blocks object may be logically divided into sections, and the sections may be searched non-sequentially. Each section may be logically divided into a number of sub-sections, and the sub-sections of the various sections may be searched non-sequentially. A new section may be added to the free blocks object, and the added section may be searched until a predetermined threshold or condition is reached, at which point non-sequential searching may begin or resume.

Dynamic write balancing in a data storage system

A multi-tiered filesystem integrates multiple types of storage devices into a contiguous filesystem storage space having regions associated with two or more tiers of storage.

Multi-tiered filesystem

Mirror relationships between system drives may be detected and/or configured automatically by writing a predetermined data pattern to a predetermined location within a system drive and then checking one or more other system drives for a mirrored copy of the same data pattern. If the data pattern is found in another SD, then it can be assumed that there is a mirror relationship between the two SDs. Failure to find the data pattern in another SD, or finding the data pattern in multiple other SDs, may indicate an error condition. Once mirror relationships are discovered, the mirror relationships can be configured into the file server automatically so that the engineer does not have to manually configure the mirror relationships. The same mechanism can be used to check mirror relationships from time to time, for example, to detect possible problems with the RAID system.

Growing community of inventors

Eastleigh, United Kingdom

Mark Stephen Laker