US5435004A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Computerized system and method for data backup
Assignee: International Business Machines Corp
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Filing: 1994-07-21
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Granted: 1995-07-18
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Expires: 2014-07-21
Abstract
Abstract A computerized data backup system and method for dynamically preserving a consistent state of primary data stored in a logical volume of a disk volume management system during processing thereof in a real-time environment. A file system command invokes a cloning of the logical volume, thereby reserving a portion for shadow-paged blocks. A read/write translation map is generated, mapping non-shadowed pages to corresponding shadowed pages in the reserved portion. Upon generating a read command for a page in the logical volume, a map search detects that a shadow page is allocated in the shadow-paged blocks corresponding to the page and effects the read. In like manner, in response to a write command to a page of the logical volume, the map is searched and a shadow page in the shadow-paged blocks is allocated if there has been no prior allocation, whereupon writing to such allocated page occurs. The backup occurs during runtime, facilitating reading from the non-shadow paged blocks during backup.
Inventors
- 👤 James O. Cox
- 👤 James M. Mott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:23
CPC Classifications
G; G06; G06F; G06F11/00; G06F11/07; G06F11/14; G06F11/1446; G06F11/1458; G06F11/1466; G06F2201/00; G06F2201/80; Y; Y10; Y10S; Y10S707/00; Y10S707/99951; Y10S707/99956
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
118 words
A computerized method for dynamically preserving a consistent state of primary data in a logical volume of a disk volume management system during runtime, comprising generating a file system command to clone said logical volume; reserving a portion of said logical volume for shadow-paged blocks in response to said file system command; generating a read/write translation map; generating a read command of a first page of said logical volume; detecting, in response to said read command, from a search of said map, whether a shadow page is allocated in said shadow-paged blocks corresponding to said first page; and reading said shadow page in response to said detecting that said shadow page corresponding to said first page is allocated.
Claim 2
Dependent Claim
118 words
A computerized method for dynamically preserving a consistent state of primary data in a logical volume of a disk volume management system during runtime, comprising generating a file system command to clone said logical volume; reserving a portion of said logical volume for shadow-paged blocks in response to said file system command; generating a read/write translation map; generating a read command of a first page of said logical volume; detecting, in response to said read command, from a search of said map, whether a shadow page is allocated in said shadow-paged blocks corresponding to said first page; and reading said shadow page in response to said detecting that said shadow page corresponding to said first page is allocated.
Claim 3
Dependent Claim
48 words
The method of claim 1 further including generating a write command to a second page of said logical volume; and detecting, in response to said write command, from a search of said map, whether a shadow page is allocated in said shadow-paged blocks corresponding to said second page.
Claim 4
Dependent Claim
28 words
The method of claim 2 further including allocating said shadow page in response to said detecting that said shadow page corresponding to said second page is not allocated.
Claim 5
Dependent Claim
22 words
The method of claim 2 further including writing to said second page in response to detecting that said shadow page is allocated.
Claim 6
Dependent Claim
47 words
The method of claim 4 wherein said logical volume includes a portion of non-shadow paged blocks; and wherein said method further includes storing, in said map and in response to said writing, a correlation between at least one of said shadow-paged blocks and said non-shadow paged blocks.
Claim 7
Dependent Claim
18 words
The method of claim 5 wherein said at least one of said shadow-paged blocks includes said second page.
Claim 8
Dependent Claim
19 words
The method of claim 1 wherein said detecting and reading steps are performed during said runtime of said system.
Claim 9
Dependent Claim
16 words
The method of claim 4 wherein said writing step is during said runtime of said system.
Claim 10
Dependent Claim
29 words
The method of claim 5 further including reading from said portion of said non-shadow paged blocks while said portion of said logical volume is reserved for said shadow-paged blocks.
Claim 11
Dependent Claim
44 words
The method of claim 9 further including generating a log of said primary data; and prior to said detecting whether said shadow page is allocated corresponding to said first or said second page, committing said data to said disk; and running out said log.
Claim 12
Dependent Claim
128 words
Apparatus for dynamically preserving a consistent state of primary data in a logical volume of a disk volume management system during runtime, comprising means for generating a file system command to clone said logical volume; means for reserving a portion of said logical volume for shadow-paged blocks in response to said file system command; means for generating a read/write translation map; means for generating a read command of a first page of said logical volume; means for detecting, in response to said read command, from a search of said map, whether a shadow page is allocated in said shadow-paged blocks corresponding to said first page; and means for reading said shadow page in response to said detecting that said shadow page corresponding to said first page is allocated.
Claim 13
Dependent Claim
128 words
Apparatus for dynamically preserving a consistent state of primary data in a logical volume of a disk volume management system during runtime, comprising means for generating a file system command to clone said logical volume; means for reserving a portion of said logical volume for shadow-paged blocks in response to said file system command; means for generating a read/write translation map; means for generating a read command of a first page of said logical volume; means for detecting, in response to said read command, from a search of said map, whether a shadow page is allocated in said shadow-paged blocks corresponding to said first page; and means for reading said shadow page in response to said detecting that said shadow page corresponding to said first page is allocated.
Claim 14
Dependent Claim
52 words
The apparatus of claim 11 further including means for generating a write command to a second page of said logical volume; and means for detecting, in response to said write command, from a search of said map, whether a shadow page is allocated in said shadow-paged blocks corresponding to said second page.
Claim 15
Dependent Claim
30 words
The apparatus of claim 12 further including means for allocating said shadow page in response to said detecting that said shadow page corresponding to said second page is not allocated.
Claim 16
Dependent Claim
24 words
The apparatus of claim 12 further including means for writing to said second page in response to detecting that said shadow page is allocated.
Claim 17
Dependent Claim
49 words
The apparatus of claim 14 wherein said logical volume includes a portion of non-shadow paged blocks; and wherein said apparatus further includes means for storing, in said map and in response to said writing, a correlation between at least one of said shadow-paged blocks and said non-shadow paged blocks.
Claim 18
Dependent Claim
17 words
The apparatus claim 15 wherein said at least one of said shadow-paged blocks includes said second page.
Claim 19
Dependent Claim
24 words
The apparatus of claim 11 wherein said means for correlating includes shadow map means for indicating used or unused states of said shadow-paged blocks.
Claim 20
Dependent Claim
25 words
The apparatus of claim 17 wherein said means for correlating further includes primary disk map means for indicating whether said non-shadow paged blocks are shadow-paged.
Claim 21
Dependent Claim
31 words
The apparatus of claim 15 further including means for reading from said portion of said non-shadow paged blocks while said portion of said logical volume is reserved for said shadow-paged blocks.
Claim 22
Dependent Claim
43 words
The apparatus of claim 19 further including means for generating a log of said primary data; and means for committing said data to said disk prior to said detecting whether said shadow page is allocated corresponding to said first or said second page.
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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) | 1998-07-17 | 1999-01-16 | 1999-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-07-17 | 2003-01-16 | 2003-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-07-17 | 2007-01-16 | 2007-07-18 | $7700.00 | Window Closed / Lapsed |