US6070224A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Virtual tape system
Assignee: EMC Corp
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Filing: 1998-04-02
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Granted: 2000-05-30
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Expires: 2018-04-02
Abstract
Abstract A method and apparatus for emulating a magnetic tape storage device with a conventional, unmodified magnetic disk storage device. I/O output requests for the emulated magnetic tape storage device are intercepted to determine whether they involve a virtual tape resource that comprises a magnetic disk storage device. Tape requests to such a resource are converted into one or more conventional magnetic disk storage requests to effect an analogous operation.
Inventors
- 👤 Douglas E. LeCrone
- 👤 Shai Hess
- 👤 Elcana Cohen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:48
CPC Classifications
G; G06; G06F; G06F3/00; G06F3/06; G06F3/0601; G06F3/0602; G06F3/0604; G06F3/0607; G06F3/0628; G06F3/0662; G06F3/0664; G06F3/0668; G06F3/0671; G06F3/0673; G06F3/0674; G06F3/0676; G06F9/00; G06F9/06; G06F9/44; G06F9/455
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
211 words
A method for operating a magnetic disk storage device as a virtual tape device available responsive to tape requests for input-output operations from a user program in user address space of a main memory of virtual operating system, the main memory including a pointer to a standard input-output module that effects input-output operations with other input-output devices, said method comprising the steps of: A) establishing a virtual tape program address space in the main memory including a server program with a command converter, an index and a second input-output module, B) altering the contents of the pointer whereby all input-output requests are handled initially by the second input-output module, C) selecting in the input-output module those tape requests for the virtual tape device and, in response thereto: i) converting in the command converter a tape request to a disk request for the magnetic disk storage device, ii) effecting an operation defined by the disk request with the magnetic disk storage device, iii) generating a return code based upon the operation of the magnetic disk storage device for the user program, and iv) updating the index thereby to maintain current correspondences between tape locations and magnetic disk storage locations, D) enabling the standard input-output module to process commands for other input-output resources.
Claim 2
Independent Claim
211 words
A method for operating a magnetic disk storage device as a virtual tape device available responsive to tape requests for input-output operations from a user program in user address space of a main memory of virtual operating system, the main memory including a pointer to a standard input-output module that effects input-output operations with other input-output devices, said method comprising the steps of: A) establishing a virtual tape program address space in the main memory including a server program with a command converter, an index and a second input-output module, B) altering the contents of the pointer whereby all input-output requests are handled initially by the second input-output module, C) selecting in the input-output module those tape requests for the virtual tape device and, in response thereto: i) converting in the command converter a tape request to a disk request for the magnetic disk storage device, ii) effecting an operation defined by the disk request with the magnetic disk storage device, iii) generating a return code based upon the operation of the magnetic disk storage device for the user program, and iv) updating the index thereby to maintain current correspondences between tape locations and magnetic disk storage locations, D) enabling the standard input-output module to process commands for other input-output resources.
Claim 3
Dependent Claim
54 words
A method as recited in claim 1 wherein said establishing step additionally generates a rule database module that identifies all resources to operate as a virtual magnetic tape storage device, said selecting step being responsive to a comparison of a resource identified in an input-output request with the information in the rule database module.
Claim 4
Dependent Claim
48 words
A method as recited in claim 2 wherein the user program is processed as a job that is initialized, said identification of resources occurring upon completion of the initialization and including the step of modifying any identified resource in the user program as a specific virtual tape device.
Claim 5
Dependent Claim
45 words
A method as recited in claim 1 wherein said step of effecting the disk request includes the step of converting a return code from the magnetic disk storage device to a corresponding one of the return codes that characterize the virtual magnetic tape storage device.
Claim 6
Dependent Claim
36 words
A method as recited in claim 1 wherein the main memory unit includes a data buffer and said step of effecting the disk request includes transferring data between the buffer and the magnetic disk storage device.
Claim 7
Dependent Claim
44 words
A method as recited in claim 5 wherein the tape request is a read request generated by a user program and said transferring step effects a transfer of data from the magnetic disk storage device through the buffer for use by the user program.
Claim 8
Dependent Claim
40 words
A method as recited in claim 5 wherein the tape request is a write request generated by a user program and said transferring step effects a transfer of data through the buffer for storage on the magnetic disk storage device.
Claim 9
Dependent Claim
58 words
A method as recited in claim 1 wherein the main memory unit includes a user data buffer in the user address space and a virtual tape data buffer in the virtual tape program address space and said step of effecting a tape request includes transferring data between the user program data buffer and the virtual tape data buffer.
Claim 10
Dependent Claim
54 words
A method as recited in claim 8 wherein the tape request is a read request generated by the user program, said transferring step effecting a transfer from the magnetic disk storage device to the virtual tape buffer and from the virtual tape buffer to the user program buffer for use by the user program.
Claim 11
Dependent Claim
51 words
A method as recited in claim 8 wherein the tape request is a write request generated by the user program, said transferring step effecting a transfer from the user program buffer to the virtual tape buffer and from the virtual tape buffer to the magnetic disk storage device for storage therein.
Claim 12
Dependent Claim
59 words
A method as recited in claim 1 wherein the tape request is other than a data transfer request, said converting step including converting the tape request to an analogous disk request and said return code conversion includes converting the return code from the magnetic disk storage device into an analogous return code for the virtual magnetic tape storage device.
Claim 13
Independent Claim
207 words
A system for operating a magnetic disk storage device as a virtual magnetic tape storage device responsive to a tape request available from a user program in user address space of a main memory of virtual operating system, the main memory including a pointer to a standard input-output module that effects input-output operations with other input-output devices, said system comprising: A) virtual tape program address space in the main memory including a server program with a command converter, an index and a second input-output module, B) means for altering the contents of the pointer whereby all input-output requests are handled initially by the second input-output module, C) means for selecting in the input-output module those commands for the virtual magnetic tape storage device, D) means responsive to the selection for converting the tape request to a disk request for the magnetic disk storage device, E) means responsive to said means for conversion for processing the disk request with the magnetic disk storage device, and F) means responsive to said means for processing for generating a return code based upon the operation of the magnetic disk storage device for the user program, and G) enabling the standard input-output module to process tape requests directed to other input-output resources.
Claim 14
Independent Claim
207 words
A system for operating a magnetic disk storage device as a virtual magnetic tape storage device responsive to a tape request available from a user program in user address space of a main memory of virtual operating system, the main memory including a pointer to a standard input-output module that effects input-output operations with other input-output devices, said system comprising: A) virtual tape program address space in the main memory including a server program with a command converter, an index and a second input-output module, B) means for altering the contents of the pointer whereby all input-output requests are handled initially by the second input-output module, C) means for selecting in the input-output module those commands for the virtual magnetic tape storage device, D) means responsive to the selection for converting the tape request to a disk request for the magnetic disk storage device, E) means responsive to said means for conversion for processing the disk request with the magnetic disk storage device, and F) means responsive to said means for processing for generating a return code based upon the operation of the magnetic disk storage device for the user program, and G) enabling the standard input-output module to process tape requests directed to other input-output resources.
Claim 15
Dependent Claim
52 words
A system as recited in claim 12 wherein said establishing means additionally comprise a rule database module that identifies all resources to operate as a virtual tape device, said selecting means being responsive to means for comparing the resources identified in a tape request with the information in said rule database module.
Claim 16
Dependent Claim
61 words
A system as recited in claim 13 wherein the user program is processed as a job that is initialized, said resource identification means operating upon completion of the initialization, said system additionally including means for modifying any resource identification in the user program to a data storage device to identify a specific virtual tape device in response to the selection process.
Claim 17
Dependent Claim
43 words
A system as recited in claim 12 wherein means for generating the return code includes means for converting a return code from the magnetic disk storage device to a corresponding one of the return codes that characterize the virtual magnetic tape storage device.
Claim 18
Dependent Claim
43 words
A system as recited in claim 12 wherein the main memory unit includes a buffer for data and said means for effecting a tape request for a data transfer includes means for transferring data between the buffer and the magnetic disk storage device.
Claim 19
Dependent Claim
37 words
A system as recited in claim 16 wherein the tape request is a read request and said transferring means effects a transfer from the magnetic disk storage device through the buffer for use by the user program.
Claim 20
Dependent Claim
33 words
A system as recited in claim 16 wherein the tape request is a write request and said transferring means effects a transfer through said buffer for storage on the magnetic disk storage device.
Claim 21
Dependent Claim
66 words
A system as recited in claim 16 wherein the input-output request is other than a data transfer request and said converting means includes means for converting the input-output request to an analogous input-output request for the magnetic disk storage device and said return code conversion includes converting the return code from the magnetic disk storage device into an analogous return code for the virtual tape device.
Claim 22
Dependent Claim
60 words
A system as recited in claim 12 wherein the main memory unit includes a user data buffer in the user address space and a virtual tape data buffer in the virtual tape program address space and said means for effecting the tape request includes means for transferring data between the user program data buffer and the virtual tape data buffer.
Claim 23
Dependent Claim
49 words
A system as recited in claim 20 wherein the tape request is a read request and said transferring means effects a transfer from the magnetic disk storage device to the virtual tape buffer and from the virtual tape buffer to the user program buffer for use by user program.
Claim 24
Dependent Claim
47 words
A system as recited in claim 20 wherein the tape request is a write request and said transferring means effects a transfer from the user program buffer to the virtual tape buffer and from the virtual tape buffer to the magnetic disk storage device for storage therein.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-05-30 | 2003-11-29 | 2004-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-05-30 | 2007-11-29 | 2008-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-05-30 | 2011-11-29 | 2012-05-30 | $7700.00 | Window Closed / Lapsed |