Method for logically consistent backup of open computer files
First Claim
1. A method of creating back-up data files in a computer operating system comprising:
- observing operating system commands to detect issuance of a command to flush and hold write operations;
intercepting said command to flush and hold write operations;
observing data storage write operations to detect a period of inactivity of said data storage write operations;
determining that said period of inactivity indicates that all stored data to be backed up is logically consistent; and
releasing said flush and hold write operations command to said operating system.
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Accused Products
Abstract
A method for providing logically-consistent computer file backups in an operating environment whose file backup provisions rely on application programs recognizing a freeze writes command but where the operating system also hosts programs that do not recognize such a command. The method intercepts a system level command issued during the backup process that signals the file system manager to flush write operations cached in memory and hold any subsequent write operations. (“Flush and Hold Writes”). File write operations are then monitored to find a quiescent period, which signals that all current file transactions are complete. Application level write operations are halted, preventing any further file transactions. The Flush and Hold Writes Command is then allowed to pass to the file system and volume manager so that these operation system components can flush to permanent storage any write operations that are cached in memory and hold any new write operations.
78 Citations
23 Claims
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1. A method of creating back-up data files in a computer operating system comprising:
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observing operating system commands to detect issuance of a command to flush and hold write operations;
intercepting said command to flush and hold write operations;
observing data storage write operations to detect a period of inactivity of said data storage write operations;
determining that said period of inactivity indicates that all stored data to be backed up is logically consistent; and
releasing said flush and hold write operations command to said operating system. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of creating back-up data files in a computer operating system comprising:
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initiating a data backup process;
signaling application programs that accept a freeze writes command to complete all current data storage write operations and halt all future data storage write operations;
issuing a flush and hold write operations command;
intercepting said flush and hold write operations command;
observing data storage write operations to detect a period of inactivity of said data storage write operations;
determining that said period of inactivity indicates that all stored data to be backed up is logically consistent;
blocking application write operations;
releasing said flush and hold write operations command to said operating system;
unblocking said application write operations after execution of said flush and hold write operations command; and
,signaling application programs that accept said freeze writes command to resume normal data storage write operations. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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16. A computer program product with encoded instructions for performing operations comprising:
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observing operating system commands to detect issuance of a command to flush and hold write operations;
intercepting said command to flush and hold write operations;
observing data storage write operations to detect a period of inactivity of said data storage write operations;
determining that said period of inactivity indicates that all stored data to be backed up is logically consistent; and
releasing said flush and hold write command to said operating system. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23)
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Specification