Error: Nagios/Icinga (Debian Squeeze) - CHECK_NRPE: Received 0 bytes from daemon. Check the remote server logs for error messages.

You monitor a remote server with Nagios or Icinga and see the following error in your Nagios/Icinga web interface:

CHECK_NRPE: Received 0 bytes from daemon. Check the remote server logs for error messages.

In /var/log/syslog on the remote server you see these messages:

Aug 23 14:20:20 server2 nrpe[11496]: Error: Request contained command arguments, but argument option is not enabled!
Aug 23 14:20:20 server2 nrpe[11496]: Client request was invalid, bailing out...

Error: Nagios/Icinga (Debian Squeeze) - CHECK_NRPE: Error - Could not complete SSL handshake.

You try to connect from your Nagios/Icinga host to a remote Nagios NRPE server like this...

/usr/lib/nagios/plugins/check_nrpe -H 9.8.7.6

... and get the following error:

root@server1:/etc/nagios-plugins/config# /usr/lib/nagios/plugins/check_nrpe -H 9.8.7.6
CHECK_NRPE: Error - Could not complete SSL handshake.
root@server1:/etc/nagios-plugins/config#

Error: OpenSUSE - Can't connect to UNIX socket /var/run/clamav/clamd: No such file or directory

You get the following error in your mail log:

Jul 7 09:13:35 hades amavis[21674]: (21674-01) (!!)ClamAV-clamd av-scanner FAILED: run_av error: Too many retries to talk to /var/run/clamav/clamd (Can't connect to UNIX socket /var/run/clamav/clamd: No such file or directory) at (eval 101) line 325.

Error: Postfix/amavisd - connect to 127.0.0.1[127.0.0.1]:10024: Connection refused

You use a Postfix setup with amavisd-new and get the following errors in your mail log:

Aug 17 14:58:33 server1 postfix/smtp[5993]: F0C57124E77: to=<info@example.com>, relay=none, delay=2524, delays=2524/0.27/0/0, dsn=4.4.1, status=deferred (connect to 127.0.0.1[127.0.0.1]:10024: Connection refused)

Or:

Aug 17 09:42:24 server1 postfix/error[7809]: 15D54124E53: to=<info@example.com>, relay=none, delay=269, delays=0.49/269/0/0.04, dsn=4.4.2, status=deferred (delivery temporarily suspended: conversation with 127.0.0.1[127.0.0.1] timed out while receiving the initial server greeting)

Error: Apache2 - mod_fcgid: HTTP request length exceeds MaxRequestLen

You try to upload a file through http to your web site running on Apache2/PHP5/mod_fcgid, and in your browser you get the error:

Error 500, Internal server error

In Apache's error log you see something like

[Thu Jan 27 15:14:15 2011] [warn] [client 192.168.1.151] mod_fcgid: HTTP request length 131484 (so far) exceeds MaxRequestLen (131072), referer: ...

Error: Fedora 15 - ssh_askpass: exec(/usr/libexec/openssh/ssh-askpass): No such file or directory

While you run virt-manager on a Fedora 15 desktop and try to connect to a KVM host, you get the following error message:

cannot recv data: ssh_askpass: exec(/usr/libexec/openssh/ssh-askpass): No such file or directory
Host key verification failed.
: Connection reset by peer

Traceback (most recent call last):
  File "/usr/share/virt-manager/virtManager/connection.py", line 1055, in _try_open
    None], flags)
  File "/usr/lib/python2.7/site-packages/libvirt.py", line 107, in openAuth
    if ret is None:raise libvirtError('virConnectOpenAuth() failed')
libvirtError: cannot recv data: ssh_askpass: exec(/usr/libexec/openssh/ssh-askpass): No such file or directory
Host key verification failed.
: Connection reset by peer

Error: Postfix - virtual_mailbox_limit is smaller than message_size_limit

You get the following error in your mail log:

Jul 13 17:12:30 mail postfix/virtual[10486]: fatal: main.cf configuration error: virtual_mailbox_limit is smaller than message_size_limit

Error: MySQL - ERROR 1153 (08S01) at line 138: Got a packet bigger than 'max_allowed_packet' bytes

You see the following error while executing a MySQL query:

ERROR 1153 (08S01) at line 138: Got a packet bigger than 'max_allowed_packet' bytes

Error: Courier-IMAP - imapd: Maximum connection limit reached for

You cannot connect to Courier-IMAP and see the following errors in your mail log:

Aug 08 11:25:45 server1 imapd: Maximum connection limit reached for ::ffff:1.2.3.4

Error: Debian Squeeze/Apache2/PHP5 - PHP Deprecated: Comments starting with '#' are deprecated in /etc/php5/apache2/conf.d/ming.ini on line 1 in Unknown on line 0

You see the following lines in Apache's error log (/var/log/apache2/error.log):

PHP Deprecated: Comments starting with '#' are deprecated in /etc/php5/apache2/conf.d/ming.ini on line 1 in Unknown on line 0
PHP Deprecated: Comments starting with '#' are deprecated in /etc/php5/apache2/conf.d/ps.ini on line 1 in Unknown on line 0