Disk acceleration using first and second storage devices
First Claim
1. A data storage system comprising:
- a first non-volatile storage device;
a second non-volatile storage device having a slower average access time and a higher capacity than the first storage device, wherein the slower average access time is the average delay that is necessary before the second non-volatile storage device can begin to write data; and
a storage controller operable to direct a first portion of data to the first storage device and a second portion of data to the second storage device,wherein the storage controller is operable to direct the second device to reserve space sufficient to accommodate the first portion of data.
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Accused Products
Abstract
A data storage device is provided. A disk device is combined with a non-volatile memory device to provide much shorter write access time and much higher data write speed than can be achieved with a disk device alone. Interleaving bursts of sector writes between the two storage devices can effectively eliminate the effect of the seek time of the disk device. Following a non-contiguous logical address transition from a host system, the storage controller can perform a look-ahead seek operation on the disk device, while writing current data to the non-volatile memory device. Such a system can exploit the inherently faster write access characteristics of a non-volatile memory device, eliminating the dead time normally caused by the disk seek time.
139 Citations
21 Claims
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1. A data storage system comprising:
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a first non-volatile storage device; a second non-volatile storage device having a slower average access time and a higher capacity than the first storage device, wherein the slower average access time is the average delay that is necessary before the second non-volatile storage device can begin to write data; and a storage controller operable to direct a first portion of data to the first storage device and a second portion of data to the second storage device, wherein the storage controller is operable to direct the second device to reserve space sufficient to accommodate the first portion of data. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A data storage system comprising:
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a first non-volatile storage device; a second non-volatile storage device having a slower average access time and a higher capacity than the first storage device, wherein the slower average access time is the average delay that is necessary before the second non-volatile storage device can begin to read data; and a storage controller operable to retrieve a first portion of data from the first storage device and a second portion of data from the second storage device, wherein the storage controller is operable to direct the second device to reserve space sufficient to accommodate the first portion of data, and wherein the storage controller is operable to subsequently direct the first storage device to send the first portion of the data to the reserved space in the second storage device.
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12. A data storage system comprising:
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a first storage device that is operable to store head data, the head data being a first portion of data in a contiguous data stream; a second storage device having a slower average access time and a higher capacity than the first storage device, the second storage device being operable to store body data, the body data being a remaining portion of data in a contiguous data stream; a head table that is operable to contain information relating to the location of the head data and the location of the body data; and a storage controller operable to satisfy data storage requests by using the head table, wherein the storage controller is operable to direct the second device to reserve space sufficient to accommodate the head data, and wherein the storage controller is operable to direct the first storage device to send the head data to the reserved space in the second storage device.
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13. A method for storing data comprising:
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receiving a write command from a host system bus to write to a data address; receiving a data fragment from the host system bus; storing a first portion of the data fragment in a first storage device; causing, prior to the completion of storing the first portion of the data fragment in the first storage device, a second storage device to be prepared to write data; and storing a remaining portion of the data fragment in the second storage device after the second storage device has been prepared, wherein causing the second storage device to be prepared to write data includes sending a seek command to a second address that is equal to the data address and an offset that is large enough to store the first portion of the data fragment. - View Dependent Claims (14, 15, 16, 17)
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18. A method for retrieving data comprising:
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receiving a read command from a host system bus to read data at a data address; determining if a first portion of the data resides on a first storage device; if the first portion of data resides on the first storage device, then reading the first portion of the data from the first storage device; causing, prior to the completion of reading the first portion of the data fragment in the first storage device, a second storage device to be prepared to read a remaining portion of the data; and reading the remaining portion of data from the second storage device after the second storage device has been prepared to read the remaining portion of the data; and if the first portion of data does not reside on the first storage device, then reading both the first portion of the data and the remaining portion of the data from the second storage device, wherein said method further comprising copying the first portion of data from the second storage device to the first storage device if it was determined that the first portion of data did not reside on the first device. - View Dependent Claims (19)
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20. A method for retrieving data comprising:
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receiving a read command from a host system bus to read data at a data address; determining if a first portion of the data resides on a first storage device; if the first portion of data resides on the first storage device, then reading the first portion of the data from the first storage device; causing, prior to the completion of reading the first portion of the data fragment in the first storage device, a second storage device to be prepared to read a remaining portion of the data; and reading the remaining portion of data from the second storage device after the second storage device has been prepared to read the remaining portion of the data; and if the first portion of data does not reside on the first storage device, then reading both the first portion of the data and the remaining portion of the data from the second storage device, wherein said method further comprising setting a flag in a head map table that indicates that the data was requested.
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21. A computer-readable medium including at least computer program code for storing data, the computer-readable medium comprising:
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computer program code for receiving a write command from a host system bus to write to a data address; computer program code for receiving a data fragment from the host system bus; computer program code for storing a first portion of the data fragment in a first storage device; computer program code for causing a second storage device to be prepared to write data prior to the completion of storing the first portion of the data fragment in the first storage device, said computer program code for causing the second storage device to be prepared to write data including at least computer program code for sending a seek command to a second address that is equal to the data address and an offset that is large enough to store the first portion of the data fragment; and computer program code for storing a remaining portion of the data fragment in the second storage device after the second storage device has been prepared.
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Specification