With Fast Compression, a differential backup will always be done unless the Data Change threshold is exceeded or the job is configured to force a full backup on certain days.
However, a full backup is not done when data change exceeds the threshold value. This happens on a database with multiple files.
Fast compression is not calulating the changed extents correctly. When running the calculation for changed extents, the fast compression process doesn't calculate across all files correctly. It reads that for the first file then processes that first file for changed extents and ignores the rest.
WORKAROUND:
Download and apply patch.
Steps to install patch after being extracted from attached RAR file.
x32
1. Navigate to C:\Program Files\Quest Software\LiteSpeed\SQL Server\Engine (or wherever Litespeed is installed)
2. Rename SLSFastCompressionx32.exe to SLSFastCompressionx32.old
3. Copy the file SLSFastCompressionx32.ex to C:\Program Files\Quest Software\LiteSpeed\SQL Server\Engine (or wherever they have Litespeed installed)
4. Rename SLSFastCompressionx32.ex to SLSFastCompressionx32.exe
x64
1. Navigate to C:\Program Files\Quest Software\LiteSpeed\SQL Server\Engine (or wherever Litespeed is installed)
2. Rename SLSFastCompressionx64.exe to SLSFastCompressionx64.old
3. Copy the file SLSFastCompressionx64.ex to C:\Program Files\Quest Software\LiteSpeed\SQL Server\Engine (or wherever they have Litespeed installed)
4. Rename SLSFastCompressionx64.ex to SLSFastCompressionx64.exe
STATUS:
Enhancement request CR96294 has been submitted to Development for consideration in a future release of Litespeed for SQL Server.
