Principle: If you look at the result of the command df -h and you are using the mdmadm software RAID 1 then you can only see the /dev/mdx partitions. eg. Filesystem Size Used Avail Use% Mounted on /dev/md2 1.8T 524G 1.2T 31% / udev 10M 0 10M 0% /dev tmpfs 3.1G 288K 3.1G 1% /run …