Set the Snapshot copy reserve with System Manager - ONTAP 9.7 and earlier
You can use ONTAP System Manager classic (avaiable in ONTAP 9.7 and earlier) to reserve space (measured as a percentage) for the Snapshot copies in a volume. By setting the Snapshot copy reserve, you can allocate enough disk space for the Snapshot copies so that they do not consume the active file system space.
The default space that is reserved for Snapshot copies is 5 percent for SAN and VMware volumes.
Click Storage > Volumes.
From the drop-down menu in the SVM field, select All SVMs.
Select the volume for which you want to set the Snapshot copy reserve.
Click More Actions > Manage Snapshots > Configuration Settings.
Type or select the percentage of volume space that you want to reserve for the Snapshot copies, and then click OK.