arg-ex-out using over half of space on partition

Hi,

I'm getting the error message, that my F5 has 0% free space - this sucks. I've noticed that this space is used mostly by /var partition:

/dev/mapper/vg--db--sda-set.12--hf1._var
                      3.0G  2.8G   23M 100% /var
`

I've found a file named arg_ex_out that uses 1,8G of disk space, and I have no idea what this is. My other F5 (active in HA configuration) has the same file, but "only" around 650M big. 

The content of the file seems to repeat itself over and over and looks like this:

`---- Command Line Args ----
::ffff:
53
---- Environment Args ----
ARGS_I=
MON_INST_LOG_NAME=/var/log/monitors/SHARED_m_dns-SHARED_2-53.log
MON_TMPL_NAME=/SHARED/m_dns
NODE_IP=::ffff:
NODE_NAME=/SHARED/
NODE_PORT=53
PATH=/sbin:/bin:/usr/sbin:/usr/bin:/usr/contrib/bin:/usr/local/bin:/usr/contrib/sbin:/usr/local/sbin:/usr/libexec
RUN_I=/Common/arg_example
TMOS_RD=2
=
---- End Args ----
---- Command Line Args ----
::ffff:
53
---- Environment Args ----
ARGS_I=
MON_INST_LOG_NAME=/var/log/monitors/SHARED_m_dns-SHARED_-53.log
MON_TMPL_NAME=/SHARED/m_dns
NODE_IP=::ffff:
NODE_NAME=/SHARED/
NODE_PORT=53
PATH=/sbin:/bin:/usr/sbin:/usr/bin:/usr/contrib/bin:/usr/local/bin:/usr/contrib/sbin:/usr/local/sbin:/usr/libexec
RUN_I=/Common/arg_example
TMOS_RD=2
=
---- End Args ----

This repeats over and over again - judging by the filesize quite a lot. Perhaps it's some sort of external monitor? Any ideas? I'll be needing to upgrade the devices quite soon, I guess I'd need the disk space