Specifying performance options (Windows DS-Client)
• In normal operating environments, you should use the default settings on the Specify backup set performance options page, and then click Next.
Additional backup set performance options are available for Windows file system backup sets, ‘classic’ (non-VSS) Microsoft SQL Server database backup sets, Oracle Server backup sets, and VSS-aware backup sets.
NOTE: This option applies only to backup items that are pure data files. It does not work on backup items with ‘backup streams’, encrypted files, sparse files, junction points, etc.
NOTE: This option does not apply to database backups if the backup set is using DS-Client Pipe as a dump option.
These performance options are provided for customers with high performance backup environments, where DS-Client could take advantage of the speed of the storage where the target backup data resides.
• Maximum pending asynchronous I/O for a file – This is the maximum number of I/O operations DS-Client will allow to queue for each file from this backup set. This is for storage devices that support better parallel disk I/O, such as NAS devices, RAID 5/10, etc. Increasing this value can significantly increase the backup speed. The optimal setting for this value depends on the storage device and network speed.
IMPORTANT: If your storage device does not support better parallel disk I/O (e.g. single read head on a physical disk, etc.), use the default value, otherwise the performance can be significantly degraded.
• Read buffer size for backup – This option adjusts the internal buffer amount that the DS-Client allocates for reading individual files for backup.
IMPORTANT: To achieve optimum backup performance, the DS-Client read buffer size might need to be different, depending on the combination of target storage device, target operating system, as well as any mid-ware involved (between the storage and the operating system).