US 8,095,726 B1 · Associating an identifier with a content unit

Abstract

Embodiments of the invention relate to associating a source string with a target content unit stored on a content addressable storage (CAS) system. This may be accomplished, in some embodiments, by storing on the CAS system an associative content unit that includes the source string in its binding part and includes the target content unit in its non-binding part.

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Claims17

Dependent claims

A method of retrieving a target content unit stored on a content addressable storage (CAS) system based upon a source identifier associated with the target content unit, wherein the target content unit is identified on the CAS system via a target content address generated based, at least in part, on the content of the target content unit, the method comprising acts of:

(A) receiving a request to access the target content unit associated with a source identifier;
(B) hashing the source identifier to generate a second content address;
(C) retrieving a second content unit identified by the second content address, wherein the second content unit stores at least the target content address;
(D) extracting the target content address from the second content unit;
(E) using the extracted target content address to retrieve the target content unit;
and,
prior to the act (A):
receiving a request to store the second content unit, wherein the second content unit comprises a binding part and a non-binding part;
generating the second content address by applying a hash function to the binding part of the content unit, but not to the non-binding part;
and
storing the second content unit on the CAS system.

8 more elements

At least one content addressable storage system that stores a target content unit that is associated with a source identifier, wherein the target content unit is identified on the at least one CAS system via a target content address generated based, at least in part, on the content of the target content unit, the at least one CAS system comprising:

at least one storage device;
and
at least one controller, coupled to the at least one storage device, that:
receives a request to access the target content unit associated with a source identifier;
hashes the source identifier to generate a second content address;
retrieves a second content unit identified by the second content address from the at least one storage device wherein the second content unit stores at least the target content address;
extracts the target content address from the second content unit;
and
uses the extracted target content address to retrieve the target content unit from the at least one storage device;
wherein the at least one controller, prior to receiving the request to access the content unit associated with the source identifier:
receives a request to store the second content unit, wherein the second content unit comprises a binding part and a non-binding part;
generates the second content address by applying a hash function to the binding part of the content unit, but not to the non-binding part;
and
stores the second content unit on the at least one storage device.

11 more elements

Dependencies are inferred from the claim text.

Description4,385 words

Summary958 words

#The present application relates to associating an identifier with a content unit stored on a content addressable storage system.

#Virtually all computer application programs rely on storage that may be used to store computer code and data manipulated by the computer code. A typical computer system includes one or more host computers that execute such application programs and one or more storage systems that provide storage.

#The host computers may access data by sending access requests to the one or more storage systems. Some storage systems require that the access requests identify units of data to be accessed using logical volume and block addresses that define where the units of data are stored on the storage system. Such storage systems are known as “block I/O” storage systems. In some block I/O storage systems, the logical volumes presented by the storage system to the host correspond directly to physical storage devices (e.g., disk drives) on the storage system, so that the specification of a logical volume and block address specifies where the data is physically stored within the storage system. In other block I/O storage systems (referred to as intelligent storage systems), internal mapping techniques may be employed so that the logical volumes presented by the storage system do not necessarily map in a one-to-one manner to physical storage devices within the storage system. Nevertheless, the specification of a logical volume and a block address used with an intelligent storage system specifies where associated content is logically stored within the storage system, and from the perspective of devices outside of the storage system (e.g., a host) is perceived as specifying where the data is physically stored.

Brief description of the drawings7 figures

#FIG. 1 is a block diagram of a computer system on which some embodiments of the invention may be implemented;

#FIG. 2 is a block diagram of a content unit having a binding portion and a non-binding portion, in accordance with some embodiments;

#FIG. 3 is a block diagram of a target content unit and an associative content unit that associates a source string with the target content unit, in accordance with some embodiments;

Detailed description3,261 words

#As discussed above, in a content addressable storage (CAS) system, content units are identified using an identifier, referred to herein as a content address, that is generated, at least in part, from at least a portion of the content of the content unit that it identifies. For example, FIG. 1 shows a computer system 100 that includes a host computer 101 which communicates with a CAS system 103. An application program 105 executing on host computer 101 may generate content units and initiate requests to store and access content units. In some embodiments, application program 105 may communicate with CAS system 103 via application programming interface (API) 107.

#An API is an interface that supports requests from application programs. That is, for example, API 107 may provide an interface that the application program uses to communicate with CAS system 103. In this way, the application program need not be aware of the details of the protocols used to communicate with the CAS system. Moreover, if it is desired to change these protocols, the application program need not be changed.

#Application program 105 may access a content unit stored on CAS system 103 by sending an access request 109 that identifies the requested content unit by it content address. Because a content address is generated, at least in part, using a hashing function, the content address is frequently a long random string. For example, the MD5 hashing algorithm yields a 128-bit hash value, that is frequently expressed as a 26 character hexadecimal string.

Facts

Application

12/059,688Filed 31 Mar 2008

Granted

10 Jan 2012

Term ends

22 Apr 2030

Estimated · how

20 years from earliest known nonprovisional domestic filing plus recorded patent term adjustment, including 752 days of adjustment. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.

Classification2 codes

G06F 12/1018
Using page tables, e.g. page table structures: involving hashing techniques, e.g. inverted page tables
G06F
Computing and data processing

Timeline

31 Mar 2008Application filedUS 12/059,688
27 Jun 2008Assigned to Emc Corporationassignment of assignor's interest
10 Jan 2012GrantedUS 8,095,726 B1
21 Sep 2016Assigned to Credit Suisse AG, Cayman Islands Branch, AS Collateral Agentsecurity agreement
21 Sep 2016Assigned to The Bank of New York Mellon Trust Company, N.A., AS Notes Collateral Agentsecurity agreement
29 Sep 2016Assigned to Emc IP Holding Company LLCassignment of assignor's interest
21 Mar 2019Assigned to The Bank of New York Mellon Trust Company, N.A.security agreement
22 Apr 2020Assigned to The Bank of New York Mellon Trust Company, N.A.security agreement
3 Nov 2021Assigned to Asap Software Express, Inc., Aventail LLC, Credant Technologies, Inc., Dell USA L.P., Dell International, L.L.C., Dell Marketing L.P., Dell Products L.P., Dell Software Inc., Dell Systems Corporation, Emc Corporation, Emc IP Holding Company LLC, Force10 Networks, Inc., Maginatics LLC, Mozy, Inc., Scaleio LLC, Wyse Technology L.L.C.release of security interest
26 Apr 2022Assigned to Dell Marketing Corporation (Successor-In-Interest To Asap Software Express, Inc.), Dell Marketing L.P. (On Behalf of Itself and AS Successor-In-Interest To Credant Technologies, Inc.), Dell USA L.P., Dell International L.L.C., Dell Products L.P., Dell Marketing Corporation (Successor-In-Interest To Force10 Networks, Inc. and Wyse Technology L.L.C.), Emc Corporation (On Behalf of Itself and AS Successor-In-Interest To Maginatics LLC), Emc IP Holding Company LLC (On Behalf of Itself and AS Successor-In-Interest To Mozy, Inc.), Scaleio LLCrelease of security interest in patents previously recorded at reel/frame (040136/0001)
20 May 2022Assigned to Dell Marketing Corporation (Successor-In-Interest To Asap Software Express, Inc.), Dell Marketing L.P. (On Behalf of Itself and AS Successor-In-Interest To Credant Technologies, Inc.), Dell USA L.P., Dell International L.L.C., Dell Products L.P., Dell Marketing Corporation (Successor-In-Interest To Force10 Networks, Inc. and Wyse Technology L.L.C.), Emc Corporation (On Behalf of Itself and AS Successor-In-Interest To Maginatics LLC), Emc IP Holding Company LLC (On Behalf of Itself and AS Successor-In-Interest To Mozy, Inc.), Scaleio LLCrelease of security interest in patents previously recorded at reel/frame (045455/0001)
23 Jun 2022Assigned to Dell Marketing L.P. (On Behalf of Itself and AS Successor-In-Interest To Credant Technologies, Inc.), Dell International L.L.C., Dell Products L.P., Dell USA L.P., Emc Corporation, Dell Marketing Corporation (Successor-In-Interest To Force10 Networks, Inc. and Wyse Technology L.L.C.), Emc IP Holding Company LLCrelease of security interest in patents previously recorded at reel/frame (053546/0001)
12 Oct 2026TodayWithin its term
22 Apr 2030Term endsEstimated, includes 752 days of adjustment

Description4,385 words

Summary958 words

#The present application relates to associating an identifier with a content unit stored on a content addressable storage system.

Brief description of the drawings7 figures

#FIG. 1 is a block diagram of a computer system on which some embodiments of the invention may be implemented;

#FIG. 2 is a block diagram of a content unit having a binding portion and a non-binding portion, in accordance with some embodiments;

#FIG. 3 is a block diagram of a target content unit and an associative content unit that associates a source string with the target content unit, in accordance with some embodiments;

Detailed description3,261 words

Associating an identifier with a content unit

Life of this patent

Associating an identifier with a content unit

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims17

Description4,385 words

Drawings

Classification2 codes

Life of this patent

Description4,385 words