Using SAR to monitor free disk space data

Maybe this post is old, however, you can get the disk space with the current version (sysstat-11.1.1)

Example:

[root@ipboss-linux ~]# sar -F 1 1
Linux 2.6.32-358.el6.x86_64 (ipboss-linux.qualif.fr)    09/23/2014      _x86_64_        (8 CPU)

11:21:16 AM  MBfsfree  MBfsused   %fsused  %ufsused     Ifree     Iused    %Iused FILESYSTEM
11:21:17 AM      4974      4869     49.47     54.55    441591    199257     31.09 /dev/sda3
11:21:17 AM        65        32     32.71     37.87     25649        39      0.15 /dev/sda1
11:21:17 AM    215269      1278      0.59      5.67  14068929     13119      0.09 /dev/sda2