US 6,028,725 AGranted

Method and apparatus for increasing disc drive performance

AssigneeEMC Corporation

InventorSteven M. Blumenau

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Abstract

A method of managing information to be stored on a storage disc in a disc drive system to achieve improved system performance. In one embodiment, data is preferentially stored on the outer tracks of the disc because system performance is greater when accessing outer tracks. Compression techniques may be employed with this embodiment to limit reductions in the storage capacity of the disc. The compression ratio can have any value, including compression ratios less than 2:1, or of F:1, wherein F is a non-integer. In another embodiment, a storage system is provided having sectors of different sizes. The different sized sectors may be on the same disc surface, on different disc surfaces, or on different disc drives. The differently sized sectors can be used to store blocks of information having different sizes to minimize the number of sectors read, thereby improving system performance.

Claims43

Dependent claims

A method of managing information to be stored on at least one disc in a storage system, the at least one disc including a plurality of sectors that are arranged to form a plurality of tracks, the method comprising steps of:

(A) forming a plurality of sector sets from the plurality of sectors, each sector set including Y main sectors and Z corresponding extended sectors;
(B) when a block of information to be written to the at least one disc is compressed by a sufficient amount to be stored within the Y main sectors of one of the plurality of sector sets, storing the block of information in a compressed state in the Y main sectors of the one of the plurality of sector sets and identifying the Z extended sectors of the one of the plurality of sector sets as being in an empty state;
and
(C) when a block of information to be written to the at least one disc is not compressed by a sufficient amount to be stored within the Y main sectors of any of the plurality of sector sets, storing the block of information in an uncompressed state partially in the Y main sectors and partially in the Z extended sectors of one of the plurality of sector sets.

1 more element

A storage system, comprising:

at least one disc including a plurality of sectors that are arranged to form a plurality of tracks;
and
a controller that manages writing of blocks of information to the at least one disc, the controller being adapted to arrange the plurality of sectors in a plurality of sector sets, each sector set including Y main sectors and Z corresponding extended sectors, the controller being further adapted to manage the writing of blocks of information to the at least one disc so that;
when a block of information to be written to the at least one disc is compressed by a sufficient amount to be stored within the Y main sectors of one of the plurality of sector sets, the controller stores the block of information in a compressed state in the Y main sectors of the one of the plurality of sector sets and identifies the Z extended sectors of the one of the plurality of sector sets as being in an empty state;
and
when a block of information to be written to the at least one disc is not compressed by a sufficient amount to be stored within the Y main sectors of any of the plurality of sector sets, the controller stores the block of information in an uncompressed state partially in the Y main sectors and partially in the Z extended sectors of one of the plurality of sector sets.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/964,442Filed 4 Nov 1997 · continuation in part
Priority: 30 Jun 1997
Granted: 22 Feb 2000
Term ends: Not estimatedThe source records don’t support an estimate.

Classification15 codes

G06F 3/0613
Improving I/O performance: in relation to throughput
G06F 3/0619
Improving the reliability of storage systems: in relation to data integrity, e.g. data losses, bit errors
G06F 3/064
Organizing or formatting or addressing of data: management of blocks
G06F 3/0674
Single storage device: disk device