How can I mount a backup HDD that is unmounted?
Answer to the question
Your file manager may provide such a feature by clicking the appropriate HDD icon. Within the terminal you may use the `mount` command.
Your device files or organized within /dev filesystem. For parallel attached drives /dev/hdXY or serial ones /dev/sdXY. Where X is your drive enumerated from a-z and Y your partition number.
For example mount the first serial attached HDDs partition 1 do the following:
mkdir /mnt/sda1 mount /dev/sda1 /mnt/sda1