US6490664B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and system for handling destage requests during shut-down in a log-structured array
Assignee: International Business Machines Corp
•
Filing: 1999-06-14
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Granted: 2002-12-03
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Expires: 2019-06-14
Abstract
Abstract Aspects for handling destage requests during shutdown in a log-structured array storage subsystem are described. In a method aspect, the method includes receiving a shut-down command, and utilizing at least three data structures for tracking destage requests when the shut-down command is received, wherein closing of open segments before completion of the shut-down is ensured. A further method aspect includes maintaining an outstanding requests list and destage requests list, forming a missing requests list based on the contents of the outstanding requests list and destage requests list when a shut-down command occurs, and tracking destage request processing with the outstanding requests list, destage requests list and missing requests list until all destage requests have been successfully completed.
Inventors
- 👤 Michael Reese Jones
- 👤 Juan Li
- 👤 Dung Kim Nguyen
- 👤 Hai-Fang yun
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:42
CPC Classifications
G; G06; G06F; G06F3/00; G06F3/06; G06F3/0601; G06F3/0602; G06F3/0614; G06F3/0619; G06F3/0628; G06F3/0655; G06F3/0659; G06F3/0668; G06F3/0671; G06F3/0683; G06F3/0689; G06F11/00; G06F11/07; G06F11/14; G06F11/1402; G06F11/1415; G06F11/1441; G06F12/00; G06F12/02; G06F12/08; G06F12/0802; G06F12/0804; G06F12/0866
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
111 words
A method for handling destage requests during shut-down in a log-structured array storage subsystem, the method comprising: receiving a shut-down command; and utilizing at least three data structures for tracking destage requests when the shut-down command is received, including utilizing an outstanding requests list and a destage requests list by comparing the outstanding requests list to the destage requests list, and forming a missing requests list based on the comparison, wherein the missing requests list further comprises a list of discrepancies between the outstanding requests list and the destage requests list, and further wherein hardening of all LTs (logical tracks) in destage requests issued before completion of the shut-down is ensured.
Claim 2
Independent Claim
111 words
A method for handling destage requests during shut-down in a log-structured array storage subsystem, the method comprising: receiving a shut-down command; and utilizing at least three data structures for tracking destage requests when the shut-down command is received, including utilizing an outstanding requests list and a destage requests list by comparing the outstanding requests list to the destage requests list, and forming a missing requests list based on the comparison, wherein the missing requests list further comprises a list of discrepancies between the outstanding requests list and the destage requests list, and further wherein hardening of all LTs (logical tracks) in destage requests issued before completion of the shut-down is ensured.
Claim 3
Dependent Claim
24 words
The method of claim 1 wherein the outstanding requests list further comprises a record of outstanding destage requests issued by a cache controller mechanism.
Claim 4
Dependent Claim
25 words
The method of claim 1 wherein the destage requests list further comprises a list of destage requests being processed by a log-structured array manager mechanism.
Claim 5
Independent Claim
109 words
A method for handling destage requests during shut-down in a log-structured array storage subsystem, the method comprising: receiving a shut-down command; utilizing at least three data structures for tracking destage requests when the shut-down command is received, including utilizing an outstanding requests list and a destage requests list by comparing the outstanding requests list to the destage requests list, and forming a missing requests list based on the comparison; and forming a retry list for destage requests reassigned to new open segments when open segments do not close successfully during shut-down, wherein hardening of all LTs (logical tracks) in destage requests issued before completion of the shut-down is ensured.
Claim 6
Independent Claim
109 words
A method for handling destage requests during shut-down in a log-structured array storage subsystem, the method comprising: receiving a shut-down command; utilizing at least three data structures for tracking destage requests when the shut-down command is received, including utilizing an outstanding requests list and a destage requests list by comparing the outstanding requests list to the destage requests list, and forming a missing requests list based on the comparison; and forming a retry list for destage requests reassigned to new open segments when open segments do not close successfully during shut-down, wherein hardening of all LTs (logical tracks) in destage requests issued before completion of the shut-down is ensured.
Claim 7
Dependent Claim
35 words
The method of claim 4 further comprising moving destage requests from the retry list to the outstanding requests list (ORL) when the ORL is empty and all destage requests have been assigned to open segments.
Claim 8
Dependent Claim
18 words
The method of claim 5 wherein array control unit request all open segments to initiate the closing process.
Claim 9
Dependent Claim
20 words
The method of claim 5 further comprising processing destage requests until the outstanding requests list and retry list are empty.
Claim 10
Dependent Claim
21 words
The method of claim 7 further comprising removing a destage request from the destage request list when the destage request completes.
Claim 11
Dependent Claim
19 words
The method of claim 7 further comprising removing a destage request from the ORL when the destage request completes.
Claim 12
Independent Claim
150 words
A method for handling destage requests during shut-down in a log-structured array storage subsystem, the method comprising: maintaining an outstanding requests list and adestage requests list; forming a missing requests list based on the contents of the outstanding requests list and destage requests list when a shut-down command occurs; tracking destage request processing with the outstanding requests list, destage requests list and missing requests list until all destage requests have been successfully completed; determining whether a destage request has failed, removing the destage request that has failed from the outstanding requests list, and adding the destage request to a retry list; and determining when the outstanding requests list is empty, and moving the destage request from the retry list to the outstanding requests list when the outstanding request list becomes empty and when the retry list is not empty and when all destage requests have been assigned to open segments.
Claim 13
Independent Claim
150 words
A method for handling destage requests during shut-down in a log-structured array storage subsystem, the method comprising: maintaining an outstanding requests list and adestage requests list; forming a missing requests list based on the contents of the outstanding requests list and destage requests list when a shut-down command occurs; tracking destage request processing with the outstanding requests list, destage requests list and missing requests list until all destage requests have been successfully completed; determining whether a destage request has failed, removing the destage request that has failed from the outstanding requests list, and adding the destage request to a retry list; and determining when the outstanding requests list is empty, and moving the destage request from the retry list to the outstanding requests list when the outstanding request list becomes empty and when the retry list is not empty and when all destage requests have been assigned to open segments.
Claim 14
Dependent Claim
16 words
The method of claim 10 further comprising requesting all open segments to initiate a closing process.
Claim 15
Independent Claim
116 words
A method for handling destage requests during shut-down in a log-structure array storage subsystem, the method comprising: maintaining an outstanding request list and a destage requests list by maintaining a record of outstanding neighborhoods in destage issued by a cache controller, and maintaining a list of destage operations being issued by a cache controller, and maintaining a list of destage operations being processed by a log-structured array manager; forming a missing request list based on the contents of the outstanding requests list and destage request list when a shut-down command occurs; and tracking destage request processing with the outstanding requests list, destage requests lists and missing request list until all destage requests have been successfully completed.
Claim 16
Independent Claim
116 words
A method for handling destage requests during shut-down in a log-structure array storage subsystem, the method comprising: maintaining an outstanding request list and a destage requests list by maintaining a record of outstanding neighborhoods in destage issued by a cache controller, and maintaining a list of destage operations being issued by a cache controller, and maintaining a list of destage operations being processed by a log-structured array manager; forming a missing request list based on the contents of the outstanding requests list and destage request list when a shut-down command occurs; and tracking destage request processing with the outstanding requests list, destage requests lists and missing request list until all destage requests have been successfully completed.
Claim 17
Independent Claim
175 words
A system for handling destage requests during shut-down in a log-structured array storage subsystem, the system comprising: a processor; an array control unit coupled to the processor, the array control unit including a cache and a controller for maintaining an outstanding requests list and destage requests list, forming a missing requests list based on the contents of the outstanding requests list and destage requests list when a shut-down command occurs, tracking destage request processing with the outstanding requests list, destage requests list and missing requests list until all destage requests have been successfully completed, determining whether a destage request has failed, removing the destage request that has failed from the outstanding requests list, adding the destage request to a retry list, determining when the outstanding requests list is empty, and moving destage requests from the retry list to the outstanding requests list when the retry list is not empty and all destage requests have been assigned to open segments; and a storage subsystem coupled to the array control unit for storing data from the cache.
Claim 18
Independent Claim
175 words
A system for handling destage requests during shut-down in a log-structured array storage subsystem, the system comprising: a processor; an array control unit coupled to the processor, the array control unit including a cache and a controller for maintaining an outstanding requests list and destage requests list, forming a missing requests list based on the contents of the outstanding requests list and destage requests list when a shut-down command occurs, tracking destage request processing with the outstanding requests list, destage requests list and missing requests list until all destage requests have been successfully completed, determining whether a destage request has failed, removing the destage request that has failed from the outstanding requests list, adding the destage request to a retry list, determining when the outstanding requests list is empty, and moving destage requests from the retry list to the outstanding requests list when the retry list is not empty and all destage requests have been assigned to open segments; and a storage subsystem coupled to the array control unit for storing data from the cache.
Claim 19
Dependent Claim
20 words
The system of claim 13 wherein the array control unit further requests all open segments to initiate a closing process.
Claim 20
Dependent Claim
34 words
The system of claim 13 wherein the array control unit further maintains the outstanding requests list as a record of outstanding neighborhoods in destage issued by a cache controller of the array control unit.
Claim 21
Independent Claim
161 words
A system for handling destage requests during shut-down in a log-structured array storage subsystem, the system comprising: a processor; an array control unit coupled to the processor, the array control unit including a cache and a controller for maintaining an outstanding requests list and destage requests list, forming a missing requests list based on the contents of the outstanding requests list and destage requests list when a shut-down command occurs, and tracking destage request processing with the outstanding requests list, destage requests list and missing requests list until all destage requests have been successfully completed, wherein the array control unit further maintains the destage requests list as a list of destage operations being processed by a log-structured array manager mechanism of the array control unit and wherein the log-structured array manager removes a destage request from the destage request list when the destage request completes; and a storage subsystem coupled to the array control unit for storing data from the cache.
Claim 22
Independent Claim
161 words
A system for handling destage requests during shut-down in a log-structured array storage subsystem, the system comprising: a processor; an array control unit coupled to the processor, the array control unit including a cache and a controller for maintaining an outstanding requests list and destage requests list, forming a missing requests list based on the contents of the outstanding requests list and destage requests list when a shut-down command occurs, and tracking destage request processing with the outstanding requests list, destage requests list and missing requests list until all destage requests have been successfully completed, wherein the array control unit further maintains the destage requests list as a list of destage operations being processed by a log-structured array manager mechanism of the array control unit and wherein the log-structured array manager removes a destage request from the destage request list when the destage request completes; and a storage subsystem coupled to the array control unit for storing data from the cache.
Claim 23
Independent Claim
161 words
A system for handling destage requests during shut-down in a log-structured array storage subsystem, the system comprising: a processor; an array control unit coupled to the processor, the array control unit including a cache and a controller for maintaining an outstanding requests list and destage requests list, forming a missing requests list based on the contents of the outstanding requests list and destage requests list when a shut-down command occurs, and tracking destage request processing with the outstanding requests list, destage requests list and missing requests list until all destage requests have been successfully completed, wherein the array control unit further maintains the destage requests list as a list of destage operations being processed by a log-structured array manager mechanism of the array control unit and wherein the log-structured array manager removes a destage request from an outstanding request list when the destage request completes; and a storage subsystem coupled to the array control unit for storing data from the cache.
Claim 24
Independent Claim
161 words
A system for handling destage requests during shut-down in a log-structured array storage subsystem, the system comprising: a processor; an array control unit coupled to the processor, the array control unit including a cache and a controller for maintaining an outstanding requests list and destage requests list, forming a missing requests list based on the contents of the outstanding requests list and destage requests list when a shut-down command occurs, and tracking destage request processing with the outstanding requests list, destage requests list and missing requests list until all destage requests have been successfully completed, wherein the array control unit further maintains the destage requests list as a list of destage operations being processed by a log-structured array manager mechanism of the array control unit and wherein the log-structured array manager removes a destage request from an outstanding request list when the destage request completes; and a storage subsystem coupled to the array control unit for storing data from the cache.
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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) | 2005-12-02 | 2006-06-03 | 2006-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-12-02 | 2010-06-03 | 2010-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-12-02 | 2014-06-03 | 2014-12-03 | $7700.00 | Window Closed / Lapsed |