Specifying performance options (Windows DS-Client)
• In normal operating environments, retain the default settings (i.e. use DS-Client’s settings) in the Specify backup set performance options screen, and click Next.
Additional backup set performance options are available for Windows File system backup sets, ‘classic’ (non-VSS) Microsoft SQL Server database backup sets, ‘classic’ Microsoft Exchange Server 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 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 may 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 may 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 may 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).