The create RAID1 example illustrates my question, at:
https://btrfs.wiki.kernel.org/index.php/UseCases#How_do_I_create_a_RAID1_mirror_in_Btrfs.3F
It shows:
mkfs.btrfs -m raid1 -d raid1 /dev/sda1 /dev/sdb1
will result in:
btrfs fi df /mount
Data, RAID1: total=1.00GB, used=128.00KB
Data:
james harvey wrote on 2015/10/19 23:49 -0400:
The create RAID1 example illustrates my question, at:
https://btrfs.wiki.kernel.org/index.php/UseCases#How_do_I_create_a_RAID1_mirror_in_Btrfs.3F
It shows:
mkfs.btrfs -m raid1 -d raid1 /dev/sda1 /dev/sdb1
will result in:
btrfs fi df /mount