US6496908B1 — Remote mirroring

Claim 1

Independent Claim 76 words

A method of mirroring source data at a plurality of remote mirrors, said method comprising: preparing a mask indicating a plurality of remote mirrors designated to receive said source data, posting said mask in a common memory accessible to a plurality of processors, each of said processors being associated with at least one of said remote mirrors; and queuing, on each of a plurality of queues corresponding to each of said remote mirrors, a mirror request.

Claim 2

Independent Claim 76 words

A method of mirroring source data at a plurality of remote mirrors, said method comprising: preparing a mask indicating a plurality of remote mirrors designated to receive said source data, posting said mask in a common memory accessible to a plurality of processors, each of said processors being associated with at least one of said remote mirrors; and queuing, on each of a plurality of queues corresponding to each of said remote mirrors, a mirror request.

Claim 3

Dependent Claim 31 words

The method of claim 1 , further comprising inspecting a status field maintained in said common memory to determine if each of said associated processors has attempted to mirror said data.

Claim 4

Dependent Claim 33 words

The method of claim 1 , further comprising inspecting a status field maintained in said common memory to determine if said data has been mirrored at each of said plurality of remote mirrors.

Claim 5

Dependent Claim 18 words

The method of claim 1 , further comprising monitoring an elapsed time since queuing of said mirror request.

Claim 6

Dependent Claim 27 words

The method of claim 4 , further comprising modifying said status field to indicate withdrawal of said mirror request when said elapsed time exceeds a predefined threshold.

Claim 7

Dependent Claim 25 words

The method of claim 1 , further comprising creating a request buffer in said common memory, said request buffer including information identifying said source data.

Claim 8

Dependent Claim 23 words

The method of claim 6 , wherein queuing said mirror request comprises associating with said mirror request a pointer to said request buffer.

Claim 9

Dependent Claim 33 words

The method of claim 1 , wherein preparing said mask comprises creating a mask in common memory, said mask having a plurality of mask elements, each of which corresponds to a remote mirror.

Claim 10

Dependent Claim 48 words

The method of claim 8 , wherein preparing said mask comprises: selecting a subset o f said plurality of mask elements; and modifying each of said selected mask elements to indicate the existence of source data to be sent to a mirror corresponding to said selected mask element.

Claim 11

Dependent Claim 40 words

The method of claim 1 , wherein preparing said mask comprises modifying a mask associated with a data storage location in said common memory, said mask having a plurality of mask elements, each of which corresponds to a remote mirror.

Claim 12

Dependent Claim 42 words

The method of claim 10 , wherein modifying said mask comprises: selecting a subset of said mask elements; and modifying each of said selected mask elements to indicate that data associated with said location is to be sent to a corresponding mirror.

Claim 13

Independent Claim 52 words

A method of mirroring source data at a plurality of remote mirrors, said method comprising: identifying a mirror request in a queue associated with a remote mirror selected from said plurality of remote mirrors; attempting execution of said mirror request; and modifying a mask in response to an outcome of said attempt.

Claim 14

Independent Claim 52 words

A method of mirroring source data at a plurality of remote mirrors, said method comprising: identifying a mirror request in a queue associated with a remote mirror selected from said plurality of remote mirrors; attempting execution of said mirror request; and modifying a mask in response to an outcome of said attempt.

Claim 15

Dependent Claim 39 words

The method of claim 12 , wherein modifying said mask comprises: selecting a mask element from said mask, said mask element corresponding to said remote mirror; and modifying said mask element in response to said outcome of said attempt.

Claim 16

Dependent Claim 50 words

The method of claim 12 , wherein said mask corresponds to a data storage location in said common memory and modifying said mask comprises altering a mask element associated with said remote mirror to indicate that data associated with said data storage location has been sent to said remote mirror.

Claim 17

Dependent Claim 21 words

The method of claim 12 , further comprising determining whether all mirror requests for mirroring said source data have been attempted.

Claim 18

Dependent Claim 19 words

The method of claim 15 , further comprising altering a status field if all mirror requests have been attempted.

Claim 19

Dependent Claim 38 words

The method of claim 12 , wherein modifying a mask in response to an outcome of said attempt comprises modifying a first mask if said attempt was unsuccessful and modifying a second mask if said attempt was successful.

Claim 20

Dependent Claim 30 words

The method of claim 17 , further comprising determining, on the basis of said first and second mask, whether all mirror requests for mirroring said source data have been attempted.

Claim 21

Dependent Claim 47 words

The method of claim 18 , wherein determining whether all mirror requests for mirroring said source data have been attempted comprises comparing said first and second masks with a third mask, said third mask containing information indicative of which remote mirrors are to receive said source data.

Claim 22

Dependent Claim 27 words

The method of claim 18 , further comprising setting a status field to a value indicative of whether all attempts to mirror said source data were successful.

Claim 23

Dependent Claim 29 words

The method of claim 18 , further comprising setting a status field to a value indicative of whether at least one attempt to mirror said source data was unsuccessful.

Claim 24

Dependent Claim 15 words

The method of claim 21 , further comprising deleting said mirror request from said queue.

Claim 25

Independent Claim 102 words

A system for mirroring source data to a plurality of remote mirrors, said system comprising: a first processor designated to communicate with a first remote mirror; a second processor designated to communicate with a second remote mirror; a first queue for receiving mirror requests for said first remote mirror, said first queue being periodically scanned by said first processor; a second queue for receiving mirror requests for said second remote mirror, said second queue being periodically scanned by said second processor; a mask providing information indicative of any pending mirror requests for sending said source data to said first and second mirrors.

Claim 26

Independent Claim 102 words

A system for mirroring source data to a plurality of remote mirrors, said system comprising: a first processor designated to communicate with a first remote mirror; a second processor designated to communicate with a second remote mirror; a first queue for receiving mirror requests for said first remote mirror, said first queue being periodically scanned by said first processor; a second queue for receiving mirror requests for said second remote mirror, said second queue being periodically scanned by said second processor; a mask providing information indicative of any pending mirror requests for sending said source data to said first and second mirrors.

Claim 27

Dependent Claim 27 words

The system of claim 23 , wherein said mask is associated with a data storage location in a common memory accessible to said first and second processor.

Claim 28

Dependent Claim 61 words

The system of claim 23 , further comprising: a request buffer containing information identifying said source data; and a first pointer associated with a first mirror request on said first queue, said first pointer pointing to said request buffer; and a second pointer associated with a second mirror request on said second queue, said second pointer pointing to said request buffer.

Claim 29

Dependent Claim 100 words

The system of claim 23 , further comprising a status field having a value selected from the group consisting of: a first value indicating existence of at least one mirror request that has not been attempted; a second value indicating that all mirror requests for said source data have completed successfully; a third value indicating that all mirror requests for said source data have been attempted and at least one attempt failed to complete successfully; and a fourth value indicating that after a lapse of a preselected time, there remains at least one mirror request that has not been attempted.

Claim 30

Dependent Claim 37 words

The system of claim 23 , further comprising: a done mask containing information indicative of successful attempts at mirroring said source data; and a failed mask containing information indicative of failed attempts at mirroring said source data.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2005-12-16	2006-06-17	2006-12-17	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2009-12-16	2010-06-17	2010-12-17	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2013-12-16	2014-06-17	2014-12-17	$7700.00	Window Closed / Lapsed

Remote mirroring

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