how can I schedule daily backup at 9:00pm in SQL server 2008?
Create a maintenance plan. SQL 2008 has a great wizard for this in SSMS which will create a SQL Agent job that you can then inspect and modify - and see the SQL syntax for future reference.
Suggestion: create a backup device first.
Use Microsoft SQL Server Management Studio to create a new Maintenance Plan (folder Management > Maintenance Plans).
This will open the designer. In the Toolbox you will find a task named Back Up Database Task, drag this onto the designer.
Right click the task to select the databases to backup.
Change the schedule of your maintenance plan to set when it will run.
Setup a Maintenance Plan using the Management tree within the SQL Server Studio:
There's a nice script here http://ola.hallengren.com/ which when run creates some sql agents jobs that perform some of the maintenance tasks you should be doing on a database.
I have schedlued my db backup daily, but i want to set retention policy as Delete the older backup folder older than 3 days.how to do it