Overview
Data can be restored/recovered from any compatible library and drive type in the CommCell. By default the system automatically identifies and restores/recovers data from any configured library in the CommCell, even if the media is not available in the original library in which the data protection operation was performed. (This is described in Restore/Recover/Retrieve From Anywhere.) Data Recovery operations use a specific data path - Library, MediaAgent, Drive Pool, and Drive - to perform the restore operations. When the default options are selected, the system automatically chooses the most appropriate data path, as described in Data Recovery Operations using Alternate Data Paths.
In some situations you may want to use another data path to perform a data recovery operation. In such a situation, you can specify the Library, MediaAgent, and for tape library, Drive Pool, and Drive.
Consider the following examples:
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You may want to use a specific MediaAgent to perform the browse and restore operation instead of the system selected default MediaAgent. For example, the default MediaAgent may be busy and you wish to use another MediaAgent which is idle, or you know the library attached to a specific MediaAgent contains the media associated with the data you wish to restore.
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The default MediaAgent may have a problem accessing the devices (library, drive) and hence you wish to use another MediaAgent sharing the library to perform the browse and restore operation.
Note
This feature is applicable only for tape library. The operation will fail if the requested data is not available in the disk library attached to the specified MediaAgent.
Considerations for Browsing Data
When you perform a browse operation, the system returns the list of files requested by the browse by reading the most recent version of the index in the MediaAgent. If the index is either not available in the MediaAgent's index cache, or not accessible to browse/restore operation then it is restored to the selected MediaAgent from any available MediaAgent. If the MediaAgent used for Browse happens to have visibility to the media then that MediaAgent is used for the browse operation. The same MediaAgent will also get selected in the subsequent restore options. If necessary you can change the MediaAgent in the subsequent restore operation.
Considerations for Browsing Data for Agents That Do Not have a Browse-able Index
Some Agents (e.g., database Agents) do not have a browse able Index. Browse operations on such Agents do not provide the option to select a MediaAgent, as an index is not used to display the data in the Browse window.
However, you can restore the data using a specific Library, MediaAgent, Drive Pool, and Drive.
Considerations for Restoring NAS Data
Consider the following while selecting an alternate path for restoring NAS data.
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If the data protection operation was performed using a MediaAgent, use another MediaAgent to perform the data recovery operation.
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If the data protection operation was performed using a MediaAgent configured to use a library attached to a NAS file server, then use a MediaAgent with a similar configuration to perform the data recovery operation.
If the appropriate MediaAgent is not selected, the restore operation will fail.
Considerations for File Level Restores with the Image Level iDataAgent
Consider the following while selecting an alternate MediaAgent for File Level Restores using the Image Level iDataAgent on Windows:
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The specified alternate MediaAgent must be on Windows, and have its index cache on an NTFS partition, or the restore operation will fail.
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For large scale file systems, the time required to rebuild the index on an alternate MediaAgent should be considered.
Other Considerations
If the media is used in another compatible library to perform the restore, the library may read the barcode differently. In such a situation, update the media barcodes and then perform the restore/recover operation.