Method and apparatus for efficient storage and retrieval of multiple content streams
Embodiments of the present invention provide disk controller operable to facilitate the efficient storage and retrieval of multiple content (data) streams to magnetic disk media. This disk controller includes an interface module, a memory module, and a processing module. The interface module is operable to couple the disk controller to a hard disk drive. The memory module and processing module in combination are operable to execute instructions that detect the geometry associated with the hard disk drive. Then the disk controller is operable to determine when the hard disk drive geometry supports assigning unique RW heads to unique content (data) streams. When the hard disk geometry supports assigning unique RW heads to unique content (data) streams, RW heads may be preferentially reserved or assigned to unique content streams wherein the RW heads are able to write unique content streams to memory locations within the hard disk drive, wherein these memory locations may be contiguous or near contiguous.
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The present invention relates generally to magnetic disk media and more particularly to the storage and retrieval of content to magnetic disk media.
BACKGROUND OF THE INVENTIONCurrently, magnetic media, such as hard disk drives are used to store (record) and retrieve (playback) multimedia content in Digital Video Recorders (DVRs). While a hard disk drive may be quite efficient at storing and playing back a single content stream, many limitations arise where two or more content streams require simultaneous access. Each stream contains data that is best accessed from contiguous locations within the hard disk drive.
Contiguous storage of such content allows faster access and reduces fragmentation. However, since the data from two or more streams is multiplexed and placed at random track locations within the hard disk drive, the read write (RW) head has to continuously move between different sections of the disk to read or write this data. Alternatively, if the content received from the multiple channels is stored within a single contiguous section or contiguous block of the disk.
The data (content) from the first channel (A) and second channel (B) alternates within the single memory location (contiguous section or block of disk) creating a potentially serious fragmentation problem. This second mode of operation is typically within most disk subsystems wherein their host is blind to the internal geometry and organization within the disk.
The structure and operation of hard disk drives is generally known. Hard disk drives include, generally, a case, a hard disk having magnetically alterable properties, and a read/write mechanism including Read/Write (RW) heads operable to write data to the hard disk by locally alerting the magnetic properties of the hard disk and to read data from the hard disk by reading local magnetic properties of the hard disk. The hard disk may include multiple platters, each platter being a planar disk.
All information stored on the hard disk is recorded in tracks, which are concentric circles organized on the surface of the platters.
Since each track typically holds many thousands of bytes of data, the tracks are further divided into smaller units called sectors. This reduces the amount of space wasted by small files. Each sector holds 512 bytes of user data, plus as many as a few dozen additional bytes used for internal drive control and for error detection and correction.
SUMMARY OF THE INVENTIONEmbodiments of the present invention are directed to systems and methods that are further described in the following description and claims. Advantages and features of embodiments of the present invention may become apparent from the description, accompanying drawings and claims.
For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings in which like reference numerals indicate like features and wherein:
Preferred embodiments of the present invention are illustrated in the FIGUREs, like numerals being used to refer to like and corresponding parts of the various drawings.
The present invention provides a method and apparatus operable to support the efficient storage and retrieval of multiple content streams to magnetic disk media that substantially addresses the above-identified needs as well as others. One embodiment provides a method with which to record simultaneous content streams to magnetic disk media. This involves receiving a first content stream via a first channel and receiving a second content stream via a second channel. A first read-write (RW) head of a multiple RW head system may be reserved or preferentially assigned to the first channel. Similarly, a second RW head of a multiple RW head disk drive may be reserved or preferentially assigned to the second channel. Memory locations (contiguous locations or blocks within the magnetic disk media) are identified that are operable to store the first and second content stream after which the RW heads are used to write the first and second content stream to disk.
Yet another embodiment provides a disk controller operable to affect efficient storage and retrieval of multiple content (data) streams to magnetic disk media. This disk controller includes an interface module, a memory module, and a processing module. The interface module is operable to couple the disk controller to a hard disk drive. The memory module and processing module in combination are operable to execute instructions that detect the geometry associated with the hard disk drive. Then the disk controller is operable to determine when the hard disk drive geometry supports assigning unique RW heads to unique content (data) streams. When the hard disk geometry supports assigning unique RW heads to unique content (data) streams, RW heads may be preferentially reserved or assigned to unique content streams wherein the RW heads are able to write unique content streams to memory locations within the hard disk drive, wherein these memory locations within the disk media may be contiguous or near contiguous.
Other embodiments of the present invention may include a hard drive operable to record and retrieve simultaneous content streams to disk that reduces fragmentation and may extend the product lifetime associated with the magnetic disk media. Yet other embodiments may include content recorders that may utilize hard disk drives or disk controllers to efficiently store simultaneous content (data) streams.
Processing module 36 may be a single processing device or a plurality of processing devices. Such a processing device may be a microprocessor, micro-controller, digital signal processor, microcomputer, central processing unit, field programmable gate array, programmable logic device, state machine, logic circuitry, analog circuitry, digital circuitry, and/or any device that manipulates signals (analog and/or digital) based on operational instructions. Memory module 65 may take the form of a single memory device or a plurality of memory devices. Such a memory device may be a read-only memory, random access memory, volatile memory, non-volatile memory, static memory, dynamic memory, flash memory, cache memory, and/or any device that stores digital information. Note that when the Disk controller 22 implements one or more of its functions via a state machine, analog circuitry, digital circuitry, and/or logic circuitry, the memory storing the corresponding operational instructions may be embedded within, or external to, the circuitry comprising the state machine, analog circuitry, digital circuitry, and/or logic circuitry. Processing module 36 stores and executes operational instructions corresponding to at least some of the steps and/or functions illustrated with reference to
Disk controller 22 may determine and track the disk geometry associated with the hard disk drive. The geometry includes both the number of available platters (disk surfaces) and RW heads within the hard disk drive.
The individual heads are mounted to arms that the actuator positions as a group. Thus, typical configurations do not allow each RW head to be independently positioned. However, other embodiments are envisioned where RW heads may be positioned independently or where more than one independently controlled RW head is assigned to a platter. Where the RW heads do not move independently, the disk controller may examine the available space on the top and bottom side of each disk within the hard disk drive. Then, the disk controller can determine whether or not sufficient contiguous disk space is available to store the two separate content streams within a cylinder of the disk drive. Where each content stream is stored to a separate platter.
For illustrative purposes,
By preferentially reserving a RW head to a content stream, fragmentation and radial RW head movement while writing or retrieving content is reduced. Additional improvements may include the ability to provide independent radial movement for each head or a set of heads thereby further improving the ability of the disk controller to identify contiguous locations on which the content of a channel may be stored.
During the defragmentation process, the disk controller may write data temporarily to memory accessible to the disk controller. This may reduce or eliminate the need to use memory available through a host device to support the defragmentation process. This reduces communicating between the host device and hard drive and further allows the host device to perform other tasks.
In summary, embodiments of the present invention provide disk controller operable to facilitate the efficient storage and retrieval of multiple content (data) streams to magnetic disk media. This disk controller includes an interface module, a memory module, and a processing module. The interface module is operable to couple the disk controller to a hard disk drive. The memory module and processing module in combination are operable to execute instructions that detect the geometry associated with the hard disk drive. Then the disk controller is operable to determine when the hard disk drive geometry supports assigning unique RW heads to unique content (data) streams. When the hard disk geometry supports assigning unique RW heads to unique content (data) streams, RW heads may be preferentially reserved or assigned to unique content streams wherein the RW heads are able to write unique content streams to memory locations within the hard disk drive, wherein these disk locations may be contiguous or near contiguous.
As one of average skill in the art will appreciate, the term “substantially” or “approximately”, as may be used herein, provides an industry-accepted tolerance to its corresponding term. Such an industry-accepted tolerance ranges from less than one percent to twenty percent and corresponds to, but is not limited to, component values, integrated circuit process variations, temperature variations, rise and fall times, and/or thermal noise. As one of average skill in the art will further appreciate, the term “operably coupled”, as may be used herein, includes direct coupling and indirect coupling via another component, element, circuit, or module where, for indirect coupling, the intervening component, element, circuit, or module does not modify the information of a signal but may adjust its current level, voltage level, and/or power level. As one of average skill in the art will also appreciate, inferred coupling (i.e., where one element is coupled to another element by inference) includes direct and indirect coupling between two elements in the same manner as “operably coupled”. As one of average skill in the art will further appreciate, the term “compares favorably”, as may be used herein, indicates that a comparison between two or more elements, items, signals, etc., provides a desired relationship. For example, when the desired relationship is that signal 1 has a greater magnitude than signal 2, a favorable comparison may be achieved when the magnitude of signal 1 is greater than that of signal 2 or when the magnitude of signal 2 is less than that of signal 1.
Although the present invention is described in detail, it should be understood that various changes, substitutions and alterations can be made hereto without departing from the spirit and scope of the invention as described by the appended claims.
Claims
1. A storage device, comprising:
- a first channel input operable to receive a first content stream streamed to a host device coupled to the storage device via a first channel;
- a second channel input operable to receive a second content stream streamed simultaneous to the first content stream to the host device via a second channel;
- a magnetic disk media operable to store content streams;
- a first read/write (RW) head;
- a second RW head; and
- a disk controller coupled to the first channel input, the second channel input, the first RW head, and the second RW head, wherein the disk controller is operable to: determine a first disk location on the magnetic disk media to store the first content stream, the first disk location comprising a plurality of substantially contiguous data blocks; determine a second disk location on the magnetic disk media to store the second content stream, the second disk location comprising a plurality of substantially contiguous data blocks; and write the first content stream to the first disk location using the first RW head and the second content stream to the second memory disk using the second RW head.
2. The storage device of claim 1, wherein the storage device is a hard drive and the magnetic disk media includes at least one platter.
3. The storage device of claim 2, wherein the first RW head is assigned to an upper face of the at least one platter, and the second RW head is assigned to a lower face of the at least one platter.
4. The storage device of claim 3, wherein the first RW head and second RW head are operable to be independently positioned within the hard drive.
5. The storage device of claim 3, wherein the disk controller is operable to write the first content stream and the second content stream to another data block using a standard storage algorithm when at least one of the first RW head and the second RW head is not available.
6. The storage device of claim 5, wherein the disk controller is operable to:
- defragment the first content stream and the second content stream to near contiguous respective disk locations after writing the first content stream and the second content stream to the another data block using the standard storage algorithm.
7. A storage system, comprising:
- a host device including a first channel input operable to receive a first content stream streamed thereto via a first channel and a second channel input operable to receive a second content stream streamed simultaneous to the first content stream thereto via a second channel;
- a magnetic disk media operable to store content streams; and
- a disk controller coupled to the host device and the magnetic disk media, wherein the disk controller is operable to: determine a first disk location on the magnetic disk media operable to store the first content stream, the first disk location comprising a plurality of substantially contiguous data blocks; determine a second disk location on the magnetic disk media operable to store the second content stream, the second disk location comprising a plurality of substantially contiguous data blocks, wherein the first disk location and second disk location are based on multiple head access to the first disk location and second disk location; and write the first content stream to the first disk location and the second content stream to the second disk location.
8. The storage system of claim 7, further comprising:
- a first tuner operable to provide the first content stream to the first channel input; and
- a second tuner operable to provide the second content stream to the second channel input.
9. The storage system of claim 7, further comprising:
- a multiple RW head memory system including a first read/write (RW) head operable to write the first content stream to the first disk location and a second read/write (RW) head operable to write the second content stream to the second disk location.
10. The storage system of claim 9, wherein the magnetic disk media is a hard disk drive that includes at least one platter and the first RW head is assigned to an upper face of the at least one platter, and the second RW head is assigned to a lower face of the at least one platter.
11. The storage system of claim 9, wherein the first RW head and second RW head are operable to be independently positioned.
12. The storage system of claim 7, wherein the disk controller is operable to write the first content stream and the second content stream to another data block when multiple RW heads are not available.
13. The storage system of claim 12, wherein the disk controller is operable to:
- defragment the first content stream and the second content stream to near contiguous respective disk locations after writing the first content stream and the second content stream to the another data block.
14. The storage system of claim 7, wherein the host device is a multimedia device.
15. A disk controller, comprising:
- an interface coupled to a hard disk drive;
- a memory; and
- a processing device coupled to the memory, wherein a combination of the processing device and the memory is operable to execute instructions that: reserve a first read/write (RW) head of a multiple RW head memory system coupled to the hard disk drive to a first content stream streamed to a host device coupled to the disk controller via a first channel; reserve a second RW head of the multiple RW head memory system to a second content stream streamed simultaneous to the first content stream to the host device via a second channel; write the first content stream to a first disk location in the hard disk drive with the first RW head, the first disk location comprising a plurality of substantially contiguous data blocks; and write the second content stream to a second disk location in the hard disk drive with the second RW head, the second disk location comprising a plurality of substantially contiguous data blocks.
16. The disk controller of claim 15, wherein the combination of the processing device and the memory is further operable to execute instructions that:
- detect a geometry associated with the hard disk drive, and wherein both the first RW head and the second RW head are reserved when the hard disk drive geometry supports assigning unique RW heads to unique content streams.
17. The disk controller of claim 15, wherein the first disk location and the second disk location are within a cylinder of the hard disk drive.
18. The disk controller of claim 15, wherein the disk controller is implemented as an integrated circuit.
19. A method for storing simultaneous content streams to magnetic disk media, comprising:
- receiving a first content stream streamed to a host device coupled to the magnetic disk media via a first channel;
- receiving a second content stream streamed simultaneous to the first content stream to the host device via a second channel;
- determining a first disk location on the magnetic disk media operable to store the first content stream, the first disk location comprising a plurality of substantially contiguous data blocks;
- determining a second disk location on the magnetic disk media operable to store the second content stream, the second disk location comprising a plurality of substantially contiguous data blocks, wherein the first disk location and the second disk location are based on multiple head access to the first disk location and the second disk location; and
- writing the first content stream to the first disk location and the second content stream to the second disk location.
20. The method of claim 19, further comprising:
- reserving a first read/write (RW) head of a multiple RW head memory system for the first channel; and
- reserving a second RW head of the multiple RW head memory system for the second channel.
Type: Application
Filed: Apr 8, 2009
Publication Date: Jul 30, 2009
Applicant: Broadcom Corporation (Irvine, CA)
Inventor: Yasantha Nirmal Rajakarunanayake (San Ramon, CA)
Application Number: 12/420,648
International Classification: G11B 21/02 (20060101);