Regular Visitor

I have a domain with 3 Server 2019 Datacenter domain controllers as follows:

 

DC1: Primary, holds global catalog and the FSMO roles

DC2: global catalog and FSMO roles present

DC3: global catalog and FSMO roles present

 

I need to do a full backup of all 3. Obviously, not all at the same time(LOL).

My questions are:

1. To backup DC2 and DC3: can I use Volume Shadow Copy service and do this while they stay up?

2. Do I have to remove the FSMO roles on DC2 and DC3 when I back them up, then bring those roles back?

3. Do I have to remove any features before I backup DC2 or DC3?

4. I'd prefer to not bring ANY of them down, and the domain is NOT Azure but is Active Directory.

    What backup method is available(for free, not Veem) to do this? Windows Backup?

5. My desire is to leave DC1 running untouched until I fully backup DC2 and DC3 seperately. After 

    those 2 DC's are backed up, do I have to remove the operation manager role and all the other FSMO roles from DC1 in order to start the backup on that?

 

Just working out my overall strategy and could use some input from some experienced admins on this.