postgres backup with raid1 I've found nothing relevant on the internet about backing up postgres DB with raid1. So here's my question

My sys admin thinks that backing up the raid1 disk ,on which a Postgres database is sitting, is adequate as a Postgres backup. He would restored it when needed.

To my understanding, backup needs to have the database stopped, at least for some commercial database like Oracle.

Is it possible to backup the database without having it stopped with a raid1 scenario?

Thanks
Tell your sys admin to search for "RAID is not a backup", whether it will provide a usable backup is irrelevant, since it doesn't protect you from database corruption, human error, and many other things.