Disc space problem

i use virtualmin on my server as control panel. i have two hard drive in my server. the first drive have 2 partition (35G and 30GB) .The others have one (70 GB). My main partititon that system run, is full %90. So mysql and my system freeze.

Drive 1
First partiton: 35 GB (completely full)
Second partiton: 30 GB (using %2)

Drive 2:
Third partiton: 70 GB (using %2)

  1. Is the fullness of the disc space, effects the mysql server?

  2. To decrease the use of main partition, is it possible to move /home directory or mail directory to other drive. If is it possible how can do this?