Why are my SQL Server backup ending as a file that is twice the size of my database? I have a SQL Server 2008 r2 database that is currently 56 GBs. When I run the following code I get a bak file that is 93 GBs. What could be causing this?

    BACKUP DATABASE [CommerceCenter]
TO DISK = 'N:\MSSQL\DATA\CC\CC_backup_tues.bak'
WITH COMPRESSION


If I use SSMS to run the backup to the same location with compression the bak file is only 8 GBs.
Most likely, it's multiple backups inside the same file. To see it:

RESTORE HEADERONLY   
FROM DISK = N'N:\MSSQL\DATA\CC\CC_backup_tues.bak' ;


If you see multiple backups in there, you have a couple of different options:


Specify a different file name per backup (I'm a huge fan of this - use date-based file names rather than days), or
Use the WITH INIT command to overwrite the last backup - this can be a bad idea if you ever need to go back more than a week