LiteSpeed for SQL Server 8.9.8 - Installation Guide

Configure LiteSpeed Defaults

LiteSpeed defaults specify the default values for various LiteSpeed backup parameters, such as compression level, processor affinity, max transfer size, buffer count and some other.

You do not need to specify these parameters each time you run a backup from the LiteSpeed UI Console, command-line interface or when using the extended stored procedures. LiteSpeed will use the pre-defined default values automatically, unless you supply a different value.

NOTE: LiteSpeed defaults typically result in the best performance. You should only modify advanced options after careful planning and testing.

To set the LiteSpeed defaults

1. In the server tree, right-click the server instance and select LiteSpeed Defaults….

2. Select an option to change its value. Review the following additional information about the LiteSpeed defaults:

   Compression level	Specifies the compression level for the backup. Valid values are 0 through 8. 0 bypasses the compression routines. The remaining values of 1 through 8 specify compression with increasingly aggressive computation. 2 is the default value for disk backups and 7 is the default value for cloud backups. For more information, see Compression Methods.
   Encryption level	By default, encryption is not used. If you select to encrypt a backup using the LiteSpeed UI Console wizards, the default encryption level is 128-bit AES. For more information, see Encryption Methods.
   Compression threads	Determines the number of threads used for the backup. You will achieve the best results by specifying multiple threads, but the exact value depends on several factors including: processors available, affinity setting, compression level, encryption settings, IO device speed, and SQL Server responsiveness. The default is n-1 threads, where n is the number of processors.
   Max transfer size	Specifies the largest unit of transfer in bytes to be used between SQL Server and LiteSpeed. The possible values are multiples of 65536 bytes (64 KB) ranging up to 4,194,304 bytes (4 MB). The default is 1048576 (1 MB).
   Buffer count	Specifies the number of SQL Server buffers available for a LiteSpeed operation. The default value is set by SQL Server.
   CPU throttle	Specifies the maximum CPU usage allowed. The argument accepts an integer value between 1 and 100. The default value is 100. This is the percentage of the total amount of CPU usage (across all enabled processors) available. TIP: Before you start tuning the CPU Throttle or Affinity parameters to adjust backup performance, try limiting the number of threads. If you decide to use an affinity value other than default, it is recommended that you limit the threading as well. You may also want to consider using Adaptive Compression to maintain backup performance. For more information, see Adaptive Compression.
   Processor affinity	Specifies the affinity mask for the process. The mask is a 64-bit integer value. By default, it is 0 and will utilize all CPUs. For more information, see Processor Affinity.
   Processor priority	Select the priority of the backup over other transactions or processes running on the same server. The default is Normal.
   Init backup set	LiteSpeed will appends the backup to an existing backup file set or tape.
   File name	Location and name of a LiteSpeed backup file. LiteSpeed uses the default SQL Server backup directory. The default file name format is %D_%DATETIME%.bak. For more information, see LiteSpeed Variables. NOTE: Fast Compression handles the naming of files automatically. For more information, see Backup Files and Folders.
   Comment	User comment written into the backup header. Is blank by default.
   Path to TSM .opt file	For more information, see Back Up and Restore to IBM Spectrum Protect™ (TSM) with LiteSpeed. See the Integration with TSM Guide for more information.

   Tip: To reset to the application default values, click Reset Original Values.

Where multiple SQL Server instances exist on one machine, you need to change the defaults for each instance individually.

Related Topics

Test Optimal Backup Settings