# Error executing probes sometimes but not always?
**URL:** https://forum.opennebula.io/t/error-executing-probes-sometimes-but-not-always/1247
**Category:** Product Support
**Created:** [September 24, 2015, 10:44pm UTC](https://forum.opennebula.io/t/error-executing-probes-sometimes-but-not-always/1247 "2015-09-24T22:44:01Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@nicolas\_belan](https://forum.opennebula.io/u/nicolas_belan)
#### Post date: [September 24, 2015, 10:44pm UTC](https://forum.opennebula.io/t/error-executing-probes-sometimes-but-not-always/1247/1 "2015-09-24T22:44:01Z")
Hello,
Running one since 4.0, but I have a strange bevavior since I upgraded my KVM hypervisor to RHEL 7.
I have:
Thu Sep 24 18:04:21 2015 [Z0][ONE][E]: Error monitoring Host hv04 (5): Error executing probes
It is only happening on rhel7, not on other hypervisor in rhel6 …
I have read [[SOLVED] Error monitoring Host (2): Error executing probes](https://forum.opennebula.io/t/solved-error-monitoring-host-2-error-executing-probes/738/4), but i have seen nothing about tmpwatch …
The problem appears not everyday, or every week …
/var/log/one/oned.log-20150912.gz:Sat Sep 12 01:32:10 2015 [Z0][ONE][E]: Error monitoring Host hv04 (5): Error executing probes
/var/log/one/oned.log-20150913.gz:Sat Sep 12 12:36:40 2015 [Z0][ONE][E]: Error monitoring Host hv04 (5): Error executing probes
Nothing between 20150913 and today …
Is there a way to have a verbose error message ?
Can you give me ways to search for ?
Thank you
Nicolas.
---
### Author:  [@nicolas\_belan](https://forum.opennebula.io/u/nicolas_belan)
#### Post date: [September 29, 2015, 11:06pm UTC](https://forum.opennebula.io/t/error-executing-probes-sometimes-but-not-always/1247/2 "2015-09-29T23:06:24Z")
\*\* Reply to myself \*\*
After reproducing the problem, I think I have found a problem in probes.
First, how to reproduce :
On the HV:
cd /var/tmp/one
vi im/kvm.d/collectd-client.rb … and wait
if you are lucky, you will get:
Vim: Caught deadly signal ABRT
Vim: Finished.
Abandon
if not, you will get:
Wed Sep 30 00:45:12 2015 [Z0][ONE][E]: Error monitoring Host HV04 (5): Error executing probes
Then … one is cancelling ALL my VMs on HV04 (they are all reset then scheduled)
The kill signal was sent by: ./im/kvm-probes.d/collectd-client-shepherd.sh
Killing the running probes returns a bad exit status so oned thinks there is a pb with the probes.
I think this is critical, because, in certain case, any user can exec a command with that string in params, waiting for probes to kill ALL vms on the HV. (I agree that no user should log into the HV… )
What do you think about my analysis ? Is it correct ?
We should enforce the “pids=$(ps axuwww | grep /collectd-client.rb | grep -v grep | awk ‘{ print $2 }’ | grep -v “^${running\_pid}$”)” line. Perhaps checking that /proc/$pids/comm == “ruby” ? (second protection ?)
Thank you for your replies 😄
Nicolas
ps: version 4.12.1