Snapshot policy for svm root volume



I am wondering about the snapshot topic for a svm root volume (especially using NFS and CIFS protocol), because I did not find any best practices related to such matter.


I have various clusters running CDOT 8.3.2 and ONTAP 9.2P1. Most of the devices are FAS2552, but I have 8040 & 8080EX as well. For each svm I am configuring 2 Load-Sharing mirrors in order to protect the svm root volumes, this work pretty good. My concerns are the following :


- Is there any best practice concerning the snapshot policy for an svm root volume ? Should it be default (6x hourly, 2x daily, 2x weekly) or is it not necessary to have this amount of snap. copies.


- what should be the snapshot reserve size ? Current configuration is more often 5% but some clusters have 10%. What should be set for these LS mirrors ?


Thank you for your help !