[Nagiosplug-help] How to interpret CRC32 errors?

[Andreas Ericsson]

Ralph.Grothe at itdz-berlin.de wrote:
> Hi,
> 
  > I would submit the script hadn't I received contemptuous
> reactions by some expert here on last occasion.
> 

You're asking people to help you on their spare time. Most of your 
questions so far have been either no-brainers that you would have been 
able to figure out for yourself had you made the effort, or of the kind 
that would take considerable effort to answer properly.

On a sidenote, it's considered very rude to cross-post unless you're 
making an announcement of some sort, so please refrain from doing so in 
the future.

> 
> The script doesn't require higher privileges than the nrpe daemon
> has,
> and it doesn't produce any output (apart from the final oneliner
> indicating the state),
> nor does it attempt to write anywhere.
> 
> If I run it at the shell under the uid of the nrpe daemon it
> works fine.
> 

Did you log in as the NRPE user or did you just su? su'ing maintains the 
environment settings of the old user, which will have effect on some 
programs.

> 
> $ /usr/local/nagios/libexec/check_hpva.sh
> 
> OK:     HP Virtual Array "va" on inwo2 all FRUs State Good
> 
> Whereas when I run it via check_nrpe I receive the to me
> meaningless CRC32 error.
> 
> $ /usr/local/nagios/libexec/check_nrpe -H 127.0.0.1 -c
> check_hpva_INWO2
> CHECK_NRPE: Response packet had invalid CRC32.
> 
> In nrpe.cfg it's defined as
> 
> $ grep check_hpva /usr/local/nagios/etc/nrpe.cfg 
> command[check_hpva_INWO2]=/usr/local/nagios/libexec/check_hpva.sh
> 
> 
> What's going on here?
> 

check_hpva.sh prints something to stderr. This causes the NRPE daemon to 
miscalculate the checksum. When the plugin does the same it arrives at 
an invalid result.

-- 
Andreas Ericsson                   andreas.ericsson at op5.se
OP5 AB                             www.op5.se
Lead Developer