Media Management Configuration: Deduplication


Use the following parameters to establish Deduplication parameters.



Allows dedupe defragmentation to complete in spite of some chunks (in percentage) exhibiting unexpected size

Definition: Specify the percentage of chunks that you can allow to fail in compaction due to size constraints when you perform a deduplication defragmentation operation to complete. When the chunks that fail are over the given percentage, then the space reclamation job is completed with error.

Default Value: 10

Range: 0 to 100

Config param to convert reconstruction to full automatically on invalid DDB backup job

Definition: Specifies that the DDB reconstruction job is transformed to a full reconstruction job when the last DDB backup job is invalid.

Default Value: 0

Range: 0 (disabled) or 1 (enabled)

Config param to mark jobs verification failed for read errors

Definition: Specifies that, during restore auxiliary copy, or synthetic full operations, if a data chunk is found that has read errors, then the Data Verification Status of the job is marked as Failed.

Default Value: 1

Range: 0 (disabled) or 1 (enabled)

Days to keep DDB on source location after successful move partition job

Definition: Specifies the number of days to keep DDB files on the source MediaAgent after a successful move partition job.

Default Value: 0 day

Range: 0 to 30 days

DDB horizontal scaling threshold free space percentage

Definition: Specifies the threshold for the percentage of free space that must be available on a deduplication database partition disk. When the available free space falls below this threshold, the software creates a new deduplication database.

Default Value: 0

Range: 0 to 50

DDB horizontal scaling threshold number of subclients per DDB

Definition: Specifies the threshold for the number of subclients that are associated with a deduplication database after which the software creates a new deduplication database for the storage policy copy. Configure a value other than zero (0) for the parameter to take effect.

Default Value: 0

DDB Reconstruction prune replay batch count

Definition: Specifies the number of prunable data blocks that can be sent in a batch to a deduplication database.

Default Value: 1000

Range: 1 to 100,000

DDB Reconstruction prune replay retry count

Definition: Specifies the number of times that DDB Reconstruction has to replay the pruned data blocks before reporting failure.

Default Value: 100,000

Range: 1 to 100,000

Deduplication pruning batch size

Definition: Specifies the number of job records that can be sent in a batch for deduplication pruning from the CommServe to the MediaAgent.

Default Value: 1000

Range: 0 to 100,000

Enable horizontal scaling of DDBs

Definition: When you enable horizontal scaling, the software regularly monitors the deduplication databases (DDBs) that exist before and after enabling the horizontal scaling. The software marks a DDB as full upon reaching the system threshold limits, and then stops association of any new subclients to the DDB. However, the existing subclients still back up to the current DDB. For more information, see Deduplication Building Block Guide.

Default Value: 1

Range: 0 (disabled) or 1 (enabled)

Maximum allowed substore configuration

Definition: Specifies the maximum number of partitions that you can configure in a deduplication database (DDB).

Default Value: 4

Range: 1 to 6

Maximum number of DDBs allowed per MediaAgent

Definition: Specifies the maximum number of deduplication database (DDB) partitions that a MediaAgent in the CommCell environment can host. When the number of DDB partitions on a MediaAgent exceed this limit, you cannot create a storage pool with a DDB partition on the MediaAgent. When horizontal scaling of DDBs is enabled, the software does not create a new DDB if any MediaAgent that the DDB is associated to reaches the threshold.

Default Value: 50

Range: 10 to 500

Maximum number of streams allowed during the deduplication database reconstruction job

Definition: Specifies the number of data streams that are used while running the deduplication database reconstruction jobs.

Default Value: 50

Range: 5 to 400

Option to retain extra DDB backups for every partition

Definition: Specifies the number of DDB backups that can be retained for each partition.

Default Value: 1

Range: 1 to 4

Usage: If multiple DDB backups for each partition are retained and the most recent DDB backup is corrupted, then you can use one of the retained DDB backups for DDB reconstruction.