A method and apparatus for reverting a disk drive to an earlier point in time is disclosed. Changes made to the drive are saved in a circular history buffer which includes the old data, the time it was replaced by new data, and the original location of the data. The circular history buffer may also be implemented by saving new data elements into new locations and leaving the old data elements in their original locations. References to the new data elements are mapped to the new location. The disk drive is reverted to an earlier point in time by replacing the new data elements with the original data elements retrieved from the history buffer, or in the case of the other embodiment, reads to the disk are mapped to the old data elements stilled stored in their original locations. The method and apparatus may be implemented as part of an operating system, or as a separate program, or in the controller for the disk drive. The method and apparatus are applicable to other forms of data storage as well. Also disclosed are method and apparatus for providing firewall protection to data in a data storage medium of a computer system.
CONTINUATION DATA
This application is a continuation-in-part of U.S. application Ser. No. 09/039,650, filed Mar. 16, 1998 and entitled "Method, Software And Apparatus For Saving, Using And Recovering Data", which is a continuation in part of Ser. No. 08/924,198, now abandoned, filed Sep. 05, 1997 entitled "Method and Apparatus for Saving and Recovering Data", the entire disclosures of which are hereby incorporated by reference herein.
Write requests are performed against one or more resources of a resource group in a persistent and atomic manner. When a write request is received, a backup resource group is updated to reflect data in a current resource group. Thereafter, the write request is performed against the backup resource group. After successfully performing the write operation(s), the backup resource group and the current resource group are swapped in an atomic, consistent manner, such that the backup resource group is now the new current resource group.
The present invention relates to improvements in the generation of an authoring file, readable by an authoring program of a DVD-Video or other interaction video media, that defines the playback structure of the content residing in a given disc's "authored content zone" and also defines the location of the assets that make up the disc's "presentation data." The improvements allow generation of an authoring file that references assets that are within the authored content zone of the medium. This allows the authoring "project" from which the final DVD-Video disc image was created to be reopened in a compatible authoring program--and to be modified by such a program--without reference to any of the original source materials.
In order to allow files structures at different locations to be synchronized, a folder tree descriptive of each set of folders is created and stored at a plurality of locations. On subsequent interconnection of the two locations a new tree is created for each location and the earliest of the old trees is used to determine which files, folders or paths of the two locations have been amended. This enables deletion or re-synchronization of files between the two locations even though files may have been worked on at different locations and at different times.
The present invention discloses a technique for restoring a database in a computer. In accordance with the present invention, the database contains objects and is stored on a data storage device connected to the computer. After a system failure, a log file is read. The log file contains one or more modifications to the database objects. Each modification has an associated data page and time stamp or sequence number. The modifications are sorted by at least one predefined sorting key value. The sorted modifications are then grouped by database object. The sorted modifications are applied to each database object in parallel.
In a data center, when a server is disconnected from the Internet because of illegal manipulation of a file, valid files (not manipulated) are copied to a standby server and the processing is resumed after a short period of disconnection. According to the invention, a control program P10 performs manipulation checks for all files listed in a manipulation checklist. If any of them is manipulated, it issues a request to disconnect from the external network and a request to assign a standby server to a control program P20 of a management server. Upon receipt of a disconnection completion signal and the address of a standby server b0, the control program P10 copies valid files (not manipulated) to the standby server b0, and for invalid files, requests the copies of their backup files. After finishing copying, the management server connects the standby server b0 to the external network to resume processing.
