Indexing Version 2 is the next-generation version of the Commvault indexing subsystem, and changes the way backup and indexing are accomplished within the MediaAgent tier.
During a data backup operation that uses Indexing Version 2 (see diagram, below), action logs containing backup metadata are first created on the Backup MediaAgent, and then played back to create one or more indexes on the Index Server MediaAgent. Since the Index Server MediaAgent is common to the entire backup set (and not local to the Backup MediaAgent), one Index Server MediaAgent can control indexing operations for multiple Backup MediaAgents.
During a data backup operation, the action logs and the full index are backed up to the same storage library used for the data backup.
Terminology
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Action logs |
Files containing metadata that are created during the data backup process. Action logs are subsequently played back to create one or more index(es). |
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Client |
A logical grouping of the agents installed on a computer. A client level is created in the CommCell Browser the first time an agent is installed on a computer. |
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Index cache |
The working area on MediaAgents where action logs and indexes are kept. By default, the index cache is created on the MediaAgent by the software installation process, and is located in the software installation directory on a local disk in the Index Server MediaAgent that produces the index. Index cache data files are not normally deleted immediately when the job completes, but may be aged out later to obtain more working space if needed. |
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Index backup |
The process by which a full index is copied to a storage library (local, network, cloud, etc.) and retained according to system rules. Each index backup (points at which an index is known to be good), can be used to recover an index in the event that the active index becomes corrupted or is unintentionally deleted. |
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Index |
A database containing the metadata for backed-up data. The index is created during the data backup process by playing action logs to it. The index is used by find, browse, restore, and other operations. |
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MediaAgent |
A logical grouping of software, server, and local storage that manages and provides high performance data movement between clients and data storage libraries. The MediaAgent software can be installed in physical, virtual, and clustered environments. |
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Metadata |
Characteristics about the data being backed up, such as file name, file size, creation date, the subject of an email, etc. This metadata is useful because it allows certain processes to obtain information about backed-up files without searching through the actual backup itself. |