Hi, yes if I doing it from the CLI as Nagios User is work fine. Here: Command definition: # 'check_tablespace' command definition_ define command{ command_name check_tablespace command_line $USER1$/check_by_ssh -H $HOSTADDRESS$ -C "/usr/local/nagios/libexec/check_tablespace $ARG1$ $ARG2$ $ARG3$ $ARG4$" Host definition: define host{ use linux-server ; Name of host template to use ; This host definition will inherit all variables that are defined ; in (or inherited by) the linux-server host template definition. host_name siper_afr alias siper_afr address 10.5.3.xxx parents routerIperAfr } service definition: define service{ use local-service ; Name of service template to use host_name siper_afr service_description tablespace check_command check_tablespace!siper!<user>!<passwd>!89 notifications_enabled 0 } Service template definition: # Local service definition template - This is NOT a real service, just a template! define service{ name local-service ; The name of this service template use generic-service ; Inherit default values from the generic-service definition max_check_attempts 4 ; Re-check the service up to 4 times in order to determine its final (hard) state normal_check_interval 5 ; Check the service every 5 minutes under normal conditions retry_check_interval 1 ; Re-check the service every minute until a hard state can be determined register 0 ; DONT REGISTER THIS DEFINITION - ITS NOT A REAL SERVICE, JUST A TEMPLATE! } thank in advance, Mirko. <div class="gmail_quote">2010/2/5 Sean McAfee <<a href="mailto:smcafee@collaborativefusion.com">smcafee@collaborativefusion.com</a>> <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> <div><div></div><div class="h5">mirko stefanelli wrote: <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> Hi to all, We run nagios on Ubuntu server with 2Gb ramm kernel version 2.6.24-23-server. Nagios version is 3.2.0. We have configured all our server (Linux REL) to execute our custom plugin by check_by_ssh. The problem is that for some server this check fails and the output is: CRITICAL - Plugin timed out while executing system call If we try to do same command, executed with check_by_shh, from user nagios on cli the command work fine! Any idea? Regards, Mirko. </blockquote> </div></div> Doing it on the CLI as the Nagios user was the right first step. Could you send your command definition, host definition, service definition, and any templates used? It's very hard to troubleshoot without those. -- Sean McAfee </blockquote></div>