how to set up monit to monitor disk-space

Solution 1:

There isn't much to do here. Your current check is syntactically correct, but may not be practical. Why do you care if space utilization is greater than 10%??!?

A typical disk check stanza would look like:

check device var with path /var
    if SPACE usage > 80% then alert

That basically will send an email if the drive is more than 80% full. Monit will also let you know once the data usage falls below that level. Also look at the Monit documentation.

Type monit status at the command line. Here's what Monit sees about your filesytem:

Filesystem 'var'
  status                            Accessible
  monitoring status                 Monitored
  permission                        755
  uid                               0
  gid                               0
  filesystem flags                  0x400
  block size                        4096 B
  blocks total                      1523090 [5949.6 MB]
  blocks free for non superuser     979860 [3827.6 MB] [64.3%]
  blocks free total                 1058477 [4134.7 MB] [69.5%]
  inodes total                      1572864
  inodes free                       1563392 [99.4%]
  data collected                    Sat, 03 Aug 2013 22:07:28