If I want to configure 20PB as Flexgroup volume for video surveillance data, can I take snapshot per day and use snaprestore recover a whole 20PB flexgroup volume in case totally failure? If yes, how long to recover 20PB huge volume size if use snaprestore? Likely snaprestore can switch to product volume quite fast.
Snaprestore is almost instant and will allow you to revert your volume to an earlier snapshot.
Please beware that all data written after the snapshot has been taken, will be lost if you use snaprestore.
I think a better alternative would be a flexclone which allows you to create a read-only clone of a volume using one of its snapshot. The advantage of flexclone is that you don't have to work on the main volume and it takes no additional space if you don't split the clone.