Using the DS-Client buffer
The DS-Client buffer is a temporary storage location on the DS-Client computer. When the Use Buffer option is selected, backup files are transferred to the buffer location first, and then the backup or restore operation is performed. This minimizes the time that the LAN must support the additional backup or restore traffic. This is particularly useful if the DS-Client's connection to the DS-System is much slower than its connection with the LAN. The DS-Client deletes all files from the DS-Client buffer after each activity, regardless of whether or not the operation was performed successfully.
The DS-Client buffer can also provide temporary storage as the database dump location for Microsoft SQL and Microsoft Exchange database backups, which avoids the need for extra disk capacity on network servers. Backup sets configured to use the DS-Client buffer also automatically benefit from the Block-level resume feature. For more information, see
“Block-level resume”.
The following DS-Client activities and backup set types use the DS-Client buffer:
Backup and Restore | The DS-Client buffer speeds up backup operations by copying files to DS-Client buffer first (at LAN speed) and then transferring files to the DS-System (at DS-System connection speed). This minimizes time that the network resource is used for the backup operation. The DS-Client speeds up restore operations by restoring files to the DS-Client buffer first (at DS-System connection speed) and then copying files to the network resource (at LAN speed). This minimizes the time that the network resource is used for the restore operation. |
Microsoft Exchange Server | The DS-Client always copies the Microsoft Exchange Server database(s) to the DS-Client buffer first, and then transfers the files to the DS-System. For extremely large Microsoft Exchange Server databases, you can specify that the backups be performed using the DS-Client Pipe option. |
Microsoft SQL Server, Oracle Server | When performing backups/restores of Microsoft SQL Server or Oracle Server databases with the Dump to DS-Client Buffer option selected, database dump(s) are created on the DS-Client buffer and then transferred to the DS-System. This provides disk space for database dumps on the DS-Client computer and eliminates the requirement for extra disk capacity on the database servers. |
For best results when using the DS-Client buffer, do the following:
• Ensure that sufficient disk capacity is available on the drive containing the DS-Client computer's buffer directory. For example, to support the backup activities for SharePoint Online data, the DS-Client buffer must provide the storage capacity calculated based on the advanced parameters SharePointOnlineBackupBatchSize (in the Miscellaneous category) and MaxSessions (in the Performance category) and the largest possible size of files that are larger than 500 MB in SharePoint Online:
SharePointOnlineBackupBatchSize x MaxSessions x Largest file size
Sample values are assigned below to provide an illustration:
• SharePointOnlineBackupBatchSize: value = 1
• MaxSessions: value = 2
• Largest possible size of files that are larger than 500 MB in your SharePoint Online Server: 10 GB
In this example, the DS-Client buffer capacity required for SharePoint Online backup activities is 1 item per batch x 2 sessions x 10GB = 200 GB
• Ensure that the buffer storage location supports the same structure as the source. For example, if your DS-Client buffer is on a Linux DS-Client, the maximum number of sub-directories allowed within a single directory is 32767. If you try to back up a path that holds more than this number of sub-directories using the DS-Client buffer, it will fail since it exceeds the maximum number of sub-directories allowed.
• Do not select the Use Buffer option for backup sets that have data on the DS-Client computer. Use Buffer copies backup files to the DS-Client buffer. From there, they are processed for backup by the DS-Client. If the DS-Client buffer directory is part of a backup set, problems can occur because the backup might catch a loop that reads the same directories being copied for backup.
• To maximize speed, provide enough credentials for all backup sets to access the DS-Client buffer directory.
The DS-Client buffer is also used by activities that access DS-Client database to create temporary files for bulk insert (for optimization of processing). If a backup set is not assigned enough credentials to create, delete, read, and write files in the DS-Client buffer directory, bulk insert operations will fail and a regular insert is used instead.