Device Configuration › Deduplication Device Management › Disk-Based Device Group Properties

Disk-Based Device Group Properties

From the list of Groups displayed, choose the device group you wish to configure and then complete the following fields.

Depending on the group selected, there are several types of properties you can configure:

Deduplication Group Properties

The following options apply to devices configured as deduplication devices.

• Max Threshold--Specifies the maximum amount of space that can be used on a disk before a job fails. When the maximum threshold is reached, Arcserve Backup fails the jobs.

  Default Value: 80%

  The Max Threshold is represented as either a percentage of the total capacity used on the disk, or as the total number of GB or MB used.

• Max # Streams--Specifies the maximum number of simultaneous streams to the device.

  Default Value: 4

• Pause data migration--Instructs Arcserve Backup to halt the data migration process. This option applies only to deduplication groups used in staging operations.

  Default Setting: Disabled

• Allow optimization in Data Deduplication backups--Directs Arcserve Backup to examine file header parameters first. The process of identifying natural boundaries and performing hash calculations is performed only on files whose header details have changed since the last backup, greatly enhancing backup throughput.

  Default Value: Enabled

  Note: You cannot optimize stream-based data (for example, MS SQL or Oracle). If you use Optimization, ensure the Reset Archive bit for backup to deduplication device option on the Operation tab in Global Options is enabled. Failure to reset the archive bits after a backup job means that Optimization considers all files to be changed, even if no changes actually took place. We recommend disabling optimization in rare situations where applications running on the machine being backed up reset the file archive bit and file attributes like modified time.

• Enable Global Deduplication--Lets you to perform deduplication on the C:\ drives of different machines.

  Note: Arcserve Backup lets you perform Global Deduplication operations on Oracle RMAN sessions.

• Delayed Disk Reclamation--Lets you reclaim disk space created by the deduplication process. Delayed disk reclamation reduces the risk of disk fragmentation.
• Expedited Disk Reclamation--Lets you immediately reclaim disk space created by the deduplication process. Although expedited disk reclamation improves the performance of disk reclamation, it can introduce disk fragmentation to the device. This option is enabled by default to improve the performance of disk reclamation.

Staging Device Group Options

The following options are available when the option, Enable Staging, is selected:

• Max Threshold--Specifies the maximum amount of space that can be used on a disk before a job fails. When the maximum threshold is reached, Arcserve Backup fails the jobs.

  Default Value: 80%

  The Max Threshold is represented as either a percentage of the total capacity used on the disk, or as the total number of GB or MB used.

• Purge data when the used disk space exceeds the Max threshold-- Instructs Arcserve Backup to delete old sessions when the disk space used for backup exceeds the Max Threshold value.
• Purge to Threshold--Available only when the Purge data when the used disk space exceeds the Max threshold option is enabled.
• Max # Streams--Specifies the maximum number of simultaneous streams to the device.

  Default Value: 2

• Enable SnapLock for this group--Available only on devices that support SnapLock technology, this option prevents data purge, or over-write until the specified retention time elapses.
• Pause Data Migration--Instructs Arcserve Backup to halt the data migration process. This option applies only to deduplication groups used in staging operations.

  Default Value: Disabled

Cloud Group Properties

The following options apply to cloud-based devices:

• Max # Streams--Specifies the maximum number of simultaneous streams to the cloud device.

  Default Value: 4