I am having issues with my backups which are done using Symantec's BACKUP EXEC 12.0, v. 1364 running on Windows 2003 Small Business Server, SP 2. Recently, I started having an issue where the compression of data did not work causing my tapes to get filled. Previously, the compression ratio would be about 1.9 : 1 meaning about 60% of my tape was used. FYI, I'm using DELL LTO-3 tapes with 400GB native size. ALl the drives being backed up are not compressed on the disk... I know that would negate the compression used by my backup system.
I have run some tests by taking random samplings of the data that is backed up using the current job settings of hardware compression if any or none. THe results are data is compressed. I have researched numerous sites including one which talked about SCSI trace utility that comes with the BE package.
My question right now is very basic, although follow up questions could spawn from this. Once a backup job starts and the hardware selects the compression mode, can compression get turned off during the job? If so, then what turns it back on?