NetApp
Storage > Volumes : Managing volumes : Scheduling automatic Snapshot copies

Scheduling automatic Snapshot copies
You can set up a schedule for making automatic Snapshot copies of a volume. You can specify the time and frequency of taking copies and the number of Snapshot copies that are saved.
Steps 
1.
From the Home tab, double-click the appropriate storage system.
2.
In the navigation pane, click Storage > Volumes.
3.
Select the volume from the volume list.
4.
Click Snapshot > Configure.
5.
Select the "Enable scheduled snapshots" check box.
6.
Type or select the number of Snapshot copies you want to keep for each unit of time.
You can keep a maximum of 255 Snapshot copies.
7.
Select one or more hours at which you want a Snapshot copy taken.
If you do not specify the time, Snapshot copies are taken each hour.
8.
Click OK to save your changes and start your Snapshot copy schedule.