Backing up the database without compromising performance I have a data base with a size up to 120 Gb and I need do a backup every night.

The problem is that the system needs stand operative all the 24 hours.

In this moments the backup takes up to 2 hours to complete.

How I can do the backup without compromising server performance?

Thanks,
Andrés
120GB should not take 2 hours


Do you have a separate disk array for backups, with a separate network interface to move the backups off the server?
If you have Enterprise Edition, can you use mirror backups
Can you do weekly full backups and daily differentials?
Is backup compression turned on (Standard in SQL Server 2008 R2+, Enterprise only in SQL Server 2008)


And without more details, it will be hard to be more specific