Data Storage and Management
Data Storage and Management |
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Media in remote storage are copied to protect data. Copies are updated as the original media are updated to ensure that a current backup of data is available. For more information about recovering data from Remote Storage, see "Repair, Recovery, and Restore" in this book.
Remote storage media (tape cartridges) are protected by media copies. Media copies are replicas that can be substituted for the original media. Data is migrated only to the original media, but can be recalled from an original or a copy. Copies are made before the original media are completely filled and are updated as the original is updated. When a media copy is completed, it can be removed from the library located with other media in the copy set, and a new media copy is started. Media copies are only created if two or more drives are available to Remote Storage in the library. Other media must be protected by outside sources. Replacing an original with a copy requires administrator intervention. Media copies can be uniquely identified.
When a media copy is used to replace damaged or lost remote storage media, Remote Storage automatically replicates the media again to ensure copy set completeness.
Partial media copies are made by the system to protect the data. These partial copies can be removed from the library and are updated when reinserted in the library. If the source of the media copy is on the shelf, the source media must be reinserted in the library for the completion of the media copy.
As many as three copy sets of remote storage media are supported. Media for the additional sets can be moved to shelf storage when they are in synch. The administrator can view the status of media copies.
For tape libraries having two or more drives available to Remote Storage, scratch media are used for making a media copy. An administrator can remove the updated media copies on a certain day after several new media copies have been made. This is especially useful for a weekend, during vacations, or initial startup. Once a copy is started, it must be returned to the library to be updated.
Remote Storage metadata exists in files which can be protected by the Windows 2000 primary backup system. Only the account used by Remote Storage has access to the metadata, by using Windows 2000 file security. Any operations requiring multiple metadata updates are transactional.
Metadata protection is provided by the Microsoft® Jet database.