I do not see any options to "use free space".
I only get - erase and use entire disk - or - custom -
The custom option is wanting me to format and mount etc. I am unable to resize, or mount.
Disappointed.
Or
delete, and
create new partitions of the size you desire. You
can't mount an
un-formatted partition because you don't mount partitions, you mount the
filesystem contained within the partition.
Personally, I create my partitions with the
fdisk application, format with the commands
mkfs -t ext4 -L <label name> /dev/<whatever> and
mkswap -L <label name> /dev/<whatever> first, then choose
Custom and
Use Existing Partitions. From there I choose which partition should be
/ and which should be
/home, (
if I choose to have a separate /home) mark all partitions to not be formatted, (
unchecked) and let the installer copy over all the files.