Best practices include tips and recommendations to help you effectively use the Backup Exec Deduplication Option. For more information about the Deduplication Option, see the Backup Exec Administrator's Guide.
The following best practices apply to deduplication disk storage devices:
Use a dedicated volume for a deduplication disk storage device.
Ensure that the volume you use for a deduplication disk storage device has enough space to hold data from multiple servers. Symantec recommends that you use a dynamic volume that can grow as needed.
Perform regular backups of the deduplication disk storage device to removable media. Create this job separately from the backup job that you use to protect the rest of your system. In the backup selection list, the Backup Exec Deduplication Storage node is located under the User Data node under Shadow Copy Components.
Perform a duplicate backup job so that you have redundant backups of the data in your deduplication disk storage device. This method is preferred over performing full backups using the deduplication writer because this method is easier to control.
Use a dedicated logon account when creating a deduplication disk storage device.
Use the spauser.exe utility if you have to change the password for the Backup Exec logon account that you specified when you created a deduplication storage folder. For more information, refer to the following tech note:
Exclude the deduplication disk storage device from your antivirus scans. If an antivirus scanner deletes or quarantines the files from the deduplication disk storage device, access to the deduplication disk storage device may be disabled.
Do not use Backup Exec's Simplified Disaster Recovery (SDR) to recover local data from the local deduplication disk storage device. SDR recovery from deduplication disk storage devices is supported for remote resources only.
On the drive properties where the deduplication disk storage device is located, ensure that the following option is not selected:.
To access the drive properties, in Windows Explorer, right-click the drive on which the deduplication disk storage device is located. Click, and then click the tab.
Do not delete any files from the deduplication disk storage device. To reclaim space from the deduplication disk storage device, refer to the following tech note:
Do not directly add any files to the deduplication disk storage device. Backup Exec does not recognize files that are placed in the deduplication disk storage device by other applications.
Review the tech note titled "Getting the most out of the Deduplication Option and Deduplication Storage Folders" for more details about using deduplication disk storage devices. The tech note is available from the following link:
The following best practices apply to using deduplication with SQL:
Set the optionas a backup job property for the SQL backup job. This option allows data to be deduplicated in the most effective way.
Use Microsoft SQL Server Management Studio to restrict SQL's use of physical memory. This option can be set for each SQL instance by selecting Properties > Memory. Restricting SQL to use 85% to 90% of total physical memory can prevent a situation in which backup rates may be reduced to 10% of the expected rate due to memory restrictions.
The following best practices help you to use the Deduplication Option effectively:
Use client-side deduplication for all deduplication jobs, except in the following situations:
The remote computer has limited or no resources available to dedicate to the deduplication process during backup jobs.
Your environment contains multi-server configurations of Microsoft SharePoint servers, Microsoft Exchange 2010 DAG servers, and Symantec Enterprise Vault servers.
You want to back up virtual machines with the Agent for VMware.
Ensure that the appropriate third-party vendor plug-in is installed for an OpenStorage Technology (OST) device and exists in the Backup Exec directory. The plug-in enables Backup Exec to detect the OST device and display the device in the server list.
Disable RAID caching on the disk where the deduplication disk storage device is located.
Ensure that each backup job has a verify job that runs after the backup job finishes, orthat is scheduled to run as a separate job.
Apply the following Microsoft hot fixes to improve performance:
Computer disk speeds have the following effects on deduplication performance:
Computers with disk speeds greater than 200 MB per second have optimal read and write performance for deduplication.
Computers with disk speeds between 150-200 MB per second have sufficient read and write speed for deduplication.
Computers with disk speeds between 100-150 MB per second have some operations with degraded performance.
Computers with disk speeds less than 100 MB per second experience poor performance. You should improve disk reads and writes before you install and run deduplication.
Connection storage area network (Fibre Channel or iSCSI), direct-attached storage (DAS), iSCSI, or internal disks are supported. Removable disks including USB, eSATA, and FireWire devices are not supported.
The Backup Exec server should have redundant connectivity to the deduplication disk storage.
The storage network must be a dedicated, low-latency network with a maximum of 1-millisecond latency per round trip.
The storage network must have enough bandwidth to meet your throughput objectives. Symantec supports the following storage network bandwidths:
Symantec requires a minimum bandwidth of 130 MB per second for read and write performance. Bandwidth that is less than 130 MB per second may be used in smaller, less resource-intensive environments. However, as usage increases, deduplication requires more bandwidth to ensure adequate throughput for deduplication processes and backups. Otherwise, performance and stability are negatively affected.