Recently, I upgraded my home server to run Ubuntu 15.04 from the previous 14.04 LTS version. The upgrade (via 14.10) was a breeze, aside from the pain in the arse of systemd and having to fix things like plexmediaserver which were no longer running – ugh.

One problem I did encounter was that none of my Perl-based nagios plugins were running anymore – giving me an ‘nrpe unable to read output’ from within the Opsview GUI. ¬†After running the plugins locally, we could see the following error:

[email protected]:/usr/local/nagios/libexec# ./check_SMART
Segmentation fault (core dumped)

To investigate, I set the core file size to unlimited, ran the script again and then ran the core file through gdb as below:

[email protected]:/usr/local/nagios/libexec# ulimit -c unlimited
[email protected]:/usr/local/nagios/libexec# ./check_SMART
Segmentation fault (core dumped)
[email protected]:/usr/local/nagios/libexec# which perl
[email protected]:/usr/local/nagios/libexec# gdb /usr/bin/perl ./core
GNU gdb (Ubuntu 7.9-1ubuntu1) 7.9
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and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
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Reading symbols from /usr/bin/perl...(no debugging symbols found)...done.

warning: core file may not match specified executable file.
[New LWP 26194]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/".
Core was generated by `/usr/bin/perl ./check_SMART'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0 0x00007fadcd2bea3e in boot_Params__Validate__XS () from /usr/local/nagios/perl/lib/x86_64-linux-gnu-thread-multi/auto/Params/Validate/XS/
(gdb) bt
#0 0x00007fadcd2bea3e in boot_Params__Validate__XS () from /usr/local/nagios/perl/lib/x86_64-linux-gnu-thread-multi/auto/Params/Validate/XS/
#1 0x00007fadce77d34b in Perl_pp_entersub () from /usr/lib/x86_64-linux-gnu/
#2 0x00007fadce775bb6 in Perl_runops_standard () from /usr/lib/x86_64-linux-gnu/

Here we can see that the Params:Validate perl module is the culprit, presumably as its not compatible with the new 5.20 Perl version. To fix this, I simply removed the old Params:Validate module and installed a new one (5.20 version) via apt:

[email protected]:/usr/local/nagios/libexec# cd /usr/local/nagios/perl/lib/
[email protected]:/usr/local/nagios/perl/lib# cd x86_64-linux-gnu-thread-multi/auto/[email protected]:/usr/local/nagios/perl/lib/x86_64-linux-gnu-thread-multi/auto# rm -rf Params/
[email protected]:/usr/local/nagios/perl/lib/x86_64-linux-gnu-thread-multi/auto# apt-get install libparams-validate-perl
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
<snipped for brevity>

Now we can test the plugins, and voila – they work:

[email protected]:/usr/local/nagios/perl/lib/x86_64-linux-gnu-thread-multi/auto# cd /usr/local/nagios/libexec/ && ./check_SMART
SMART WARNING - /dev/sdf /dev/sda /dev/sdb /dev/sdc /dev/sdd /dev/sde WARNING Airflow_Temperature_Cel Failed on: In_the_past /dev/sdg

Happy monitoring!