NFS second disk -

I assembled an NFS server about a month ago and it seems to work properly, has been in use continuouslysince then ... However I installed two 3TB discs and only enabled /dev/sda. I would like to simply copy data from time to time from /dev/sda to /dev/sdb. I cant work out how to accomplish this and am about at the point of just moving the second disk into a works station and doing an rsync occasionally for a back up. I would prefer to keep the /sda/sdb drive in the server. Presently the server has in fstab: [bobg@ASRock-J3455M ~]$ cat /etc/fstab # # /etc/fstab # Created by anaconda on Thu Apr 12 16:33:43 2018 # # Accessible filesystems, by reference, are maintained under '/dev/disk' # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info # /dev/mapper/fedora-root / ext4    defaults        1 1 UUID=d9715d27-426c-4e6f-8741-ea052fe7bab2 /boot                   ext4    defaults        1 2 UUID=1128-BE6B          /boot/efi vfat    umask=0077,shortname=winnt 0 2 /dev/mapper/fedora-home /home ext4    defaults        1 2 /dev/mapper/fedora-swap swap and for exports: [bobg@ASRock-J3455M ~]$ cat /etc/exports /home    192.168.1.0/24(rw,no_root_squash) #/exports/home 192.168.1.0/24(rw,sync,insecure,no_root_squash,no_subtree_check,fsid=0) # /exports   192.168.1.0/255.255.255.0(ro,sync) # /exports/home/public/192.168.1.0/255.255.255.0(rw,sync) # /exports 192.168.54.0/255.255.255.0(ro,sync) Can anyone tell me what I need to do or point to an instruction for tobe able to access the second disk? Bob -- Bob Goodwin - Zuni, Virginia, USA http://www.qrz.com/db/W2BOD box10 FEDORA-27/64bit LINUX XFCE Fastmail POP3