Higher compression levels result in smaller backup files, but they also may consume additional CPU. If the server does not have sufficient CPU, then the backup may take longer to complete. The Backup Analyzer evaluates different settings, such as compression level, striping, and backup destinations, to help you determine optimal backup settings.
NOTE: When running the Backup Analyzer, follow these guidelines for the best results:
Minimum: 1 GB sample size.
Recommendation: 10 GB sample size. The combination of compression levels, encryption options, and backup locations should be considered. For example, if you sample 4 GB of data with 10 different tests, LiteSpeed will take the same amount of time as it takes to back up 40 GB. On very large databases, you can speed up the analysis by reducing the number of backup combinations or by reducing the amount of sample data.
The Backup Analyzer wizard guides you through selecting the backup parameters to test. The wizard tests all of the different combinations of your selected parameters by backing up a portion of the database. It does not interfere with existing backup schedules or sets.
To run the Backup Analyzer wizard
Select the Backup Manager pane (CTRL+1).
Right-click the database and select Backup Analyzer Wizard.
NOTE: After the required number of bytes is received for analysis, the process is intentionally aborted. This generates the VDI error messages in the LiteSpeed log files and the SQL Server error log. Please ignore them.
You can schedule analyzing from within the Backup Analyzer Wizard. An SQL Server job with the name "LiteSpeed Analyzer SERVERNAME.DATABASENAME" is created. View the list of Backup Analyzer jobs directly from the Backup Analyzer tab by clicking "Show Analyzer Jobs." Right-click on the job. You can change schedule, start/stop, disable or even delete the job. To view the script, select the "View in Job Manager" option and open the job properties from the Job Manager module. You can then go to the job step details.
The Backup Analyzer tab consists of the toolbar, graph, and grid. The Backup Analyzer toolbar is used to select the following items:
The Backup Analyzer tab presents the test results in a graph and grid format:
Graph—Displays the backup duration and compression amount for each test in a bar graph so you can easily compare the results between size and duration. If you hover the mouse over the bar graph, test number, size, and duration are displayed. If you select a test in the grid, LiteSpeed indicates the corresponding test in the bar graph with a yellow border around it. You can view previous tests by changing the Existing test field.
Grid—Displays the details of each test in columnar format. LiteSpeed indicates its recommendation with the number indicated first in the Test Number column and a yellow box around the test bar graph. Review the following for additional information:
Tip: .Use the Grid horizontal scroll bar to view other table columns.
The number assigned by the Backup Analyzer.
The compression level that is used for a particular database backup test.
Indicates enabled encryption for the database backup.
The approximate time allotted to run the database backup.
|Estimated Backup Size (MB)||
The approximate size of the backed up database.
|Database Size (MB)||
The amount of disk space the database occupies.
The amount of disk space you can save with this compression ratio.
Data compression ratio.
|Read Speed (MB/Sec)||Maximum read speed.|
|Throughput (MB/Sec)||Actual speed of processing data (compression and encryption).|
|Backup Speed (MB/Sec)||Virtual write speed of the backup. Compare this value to Throughput and Read Speed to determine if you are experiencing a write-bound issue.|
|Write Speed (MB/Sec)||Actual write speed. It shows how quickly the compressed data stream is written to the destination disk.|
|Stripes||Number of stripes associated with the backup.|
|Destination||Backup destination directory location.|
|Threads||Number of threads associated with the backup.|
You can double-click a row for more information about the test.
Tip: For panes that have grids, you can sort, group, move, and remove the columns: