Eliminating Backup Failures
You can use filters to exclude items which consistently fail and that are not integral to the operation of the system or applications. Some items fail because they are locked by the operating system or application and cannot be opened at the time of the data protection operation. This often occurs with certain system-related files and database application files. Also, keep in mind that you will need to run a full backup after adding failed files to the filter in order to remove them from backups.
Eliminating Restore Failures
When restoring data, do not set a quota for an object (such as a volume, directory, or user) that is lower than the amount already used. Doing so may cause improper results for data recovery operations.
Do not configure the content of a subclient while the parent node or any sibling subclient has a data backup or restore operation currently running on it.
Reconfiguring Default Subclient Content
We recommend that you do not re-configure the content of a default subclient because this would disable its capability to serve as a catch-all entity for client data. As a result, some data will not get backed up or scanned.
Restore by Job
Avoid running restores by jobs for jobs associated with the default backup set, if you do not want to restore the operating system files or directories. The entire content of the backed up client will be restored and the client where you are restoring might run out of space.
On-Demand Operations
On-demand backups allow content to be specified as an external input when starting a backup. Traditional backups are performed by using subclients, which contain fixed content configured prior to performing the backup operation. To perform on-demand backups with multiple streams, create multiple content files. As each content file directly translates into a stream, we recommended that each stream is reading off a different disk. Concurrent read operations on the same disk cause performance degradation. For more information on content files, refer to Defining Content for On-Demand Data Protection Operations.
Optimizing the CPU Usage on Production Servers
In virtualized environments (e.g.,LPAR, WPAR, Solaris Zones etc.,) where dedicated CPUs are not allocated, backup jobs may result in high CPU usage on production servers. The following measures can be taken to optimize the CPU usage:
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Set the appropriate priority for the backup jobs using the dNICEVALUE registry key to restrict allocation of all the available CPU resources to a specific backup job. By default, Commvault processes run at default priority on the client computers. If there are available CPU cycles, then Commvault processes will use the available CPU for backup and restore operations. If the CPU is being used by other application or system processes, Commvault processes will not preempt them. In such cases, if you want to give higher priority to other application or system processes, which are running at the default priority, you can modify the priority of the Commvault process using the following steps:
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From the CommCell Browser, navigate to Client Computers.
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Right-click the <Client> and click Properties.
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Click Advanced and then click Additional Settings tab.
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Click Add.
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In the Name field, type dNICEVALUE.
The Category and Type fields are populated automatically.
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In the Value field, type the appropriate value.
For example, 15.
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Click OK.
Note
Restart the services on the client after setting this key.
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Client side compression, encryption, and deduplication operations also consume considerable CPU resources. Moving these operations from the client to the MediaAgent will help reduce the additional CPU load.
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Using a proxy server for IntelliSnap operations will move the CPU load onto the proxy thereby decreasing the overhead on the production servers further.
Subclients with Overlapping Content
Do not create subclients configured for backup and archiving with overlapping content in the same backup set.
If you require two subclients with overlapping content, create the subclients using different backup sets.