EMC DL3D 1500 Administrator's Manual page 61

Note: If all tape drives are assigned to other virtual tape libraries, you
must edit or delete existing virtual tape libraries to make tape drives to
available for a new virtual tape library.
8. Select Enable De-Duplication to enable de-duplication for this
virtual tape library. By default, de-duplication is not enabled.
Once the virtual tape library has been created, de-duplication
cannot be enabled or disabled for this virtual tape library.
9. If you want to use scheduled de-duplication, select Enable
Backup Window and specify the backup window. De-duplication
will not occur during this time window each day. Only one
backup window may be set per virtual tape library. By default,
selecting only Enable De-duplication enables immediate
de-duplication for the virtual tape library.
a. From the list box, select the start time for the backup window.
b. From the list box, select the end time for the backup window.
Note: If de-duplication does not complete before the next backup
window occurs, de-duplication of the previous day's backup data will
continue until it finishes. This can cause your backup window to be
extended. De-duplication of the current backup will not occur until the
backup window expires.
10. Click Apply to create the virtual tape library.
The virtual tape library is added to the virtual tape library list.
Figure 7 illustrates an example of adding a virtual tape library.
Configuring and Managing Virtual Tape Libraries
Configuring virtual tape libraries 61