Linux Monitoring

Skip Prerequisites, Web and LPAR2RRD tabs in case of configuring Virtual Appliance, Docker or a Container

  • LPAR2RRD server can be hosted on any Unix or Linux Operating system
  • Perl: arbitrary version coming with the OS with some additional modules, more below
  • Apache or any other Web server
Skip it in case of configuring Virtual Appliance
HW sizing

User creation

  • create lpar2rrd user under root: 
    # useradd -c "LPAR2RRD user" -m lpar2rrd
  • Increase limits for user lpar2rrd and the WEB server user (under root)
    • Linux 
      # vi /etc/security/limits.conf

lpar2rrd        hard    stack           -1
lpar2rrd        soft    stack           -1
lpar2rrd        hard    data            -1
lpar2rrd        soft    data            -1
lpar2rrd        hard    nofile          32768 
lpar2rrd        soft    nofile          32768 
lpar2rrd        hard    nproc           5000
lpar2rrd        soft    nproc           5000

apache          hard    stack           -1
apache          soft    stack           -1
apache          hard    data            -1
apache          soft    data            -1
If you have already running STOR2RRD on the same host then skip to Web tab.

Linux RedHat, CentOS

  • RHEL 8: enable the codeready-builder-for-rhel-8-*-rpms repository 
    # ARCH=$( /bin/arch )
# subscription-manager repos --enable "codeready-builder-for-rhel-8-${ARCH}-rpms"
  • CentOS 8: enable the PowerTools repository 
    # yum config-manager --set-enabled PowerTools
or
# dnf config-manager --set-enabled powertools
    You can also just open /etc/yum.repos.d/CentOS-Linux-Linux-PowerTools.repo with a text editor and set enabled= to 1 instead of 0

  • RedHat, CentOS: all versions 
    # umask 0022 
# yum install perl rrdtool rrdtool-perl httpd mod_ssl
# yum install epel-release
# yum install perl-TimeDate perl-HTTP-Date perl-Env perl-CGI perl-Data-Dumper perl-LWP-Protocol-https perl-libwww-perl perl-Time-HiRes perl-IO-Tty
# yum install perl-PDF-API2 perl-JSON-XS perl-XML-Simple perl-XML-NamespaceSupport perl-URI perl-XML-SAX-Base perl-XML-SAX perl-XML-LibXML
# yum install ed bc libxml2 sharutil
    Follow this for installing perl-PDF-API2 on RHEL/CentOS 8
    Note that rrdtool-perl and epel-release (this is necessary only for PDF reporting) might not be in your RedHat base repository especially for RHEL 6.x and olders.
    Install CentOS package instead rrdtool-perl-1.4.8-9.el7.x86_64.rpm and epel-release-7-11.noarch.rpm

Linux Debian, Ubuntu

    # umask 0022 
# apt-get install apache2 perl rrdtool ed bc
# apt-get install librrdp-perl libxml-sax-perl libxml-simple-perl libtimedate-perl libenv-sanctify-perl libcgi-pm-perl libdata-dumper-simple-perl libpdf-api2-perl libxml2-utils
# apt-get install liblwp-protocol-https-perl libcrypt-ssleay-perl libio-socket-ssl-perl libmozilla-ldap-perl libxml-parser-perl
Skip it in case of configuring Virtual Appliance

Apache download

  • Linux CentOS, RedHat 
    # yum install httpd
  • Linux Debian, Ubuntu 
    # apt-get install httpd

Apache configuration

Apache start / restart

    Command depends on Apache version, one of these should work: 
    # apachectl restart
# /opt/freeware/apache/sbin/apachectl restart
# /etc/init.d/httpd restart
# service apache2 restart
    If you have firewall enabled then enable LPAR2RRD communication by: 
    # firewall-cmd --add-service=http --permanent
# firewall-cmd --add-service=https --permanent
# firewall-cmd --add-port=8162/tcp --permanent

# firewall-cmd --reload

Test web pages

    Point your web browser to http://<your lpar2rrd host>/lpar2rrd/ as soon as you configure LPAR2RRD
    Do not forget to ensure that Apache starts after the OS reboot (there must be a starting script in /etc/rc.... )

Apache configuration per platform and version

  • Linux CentOS, RedHat


    Append at the end of /etc/httpd/conf/httpd.conf following 
    # vi /etc/httpd/conf/httpd.conf

AddHandler cgi-script .sh
# DocumentRoot  "/home/lpar2rrd/lpar2rrd/www/"
Alias /lpar2rrd  "/home/lpar2rrd/lpar2rrd/www/"
<Directory "/home/lpar2rrd/lpar2rrd/www/">
    AllowOverride AuthConfig
    Options Indexes FollowSymLinks
    Require all granted
</Directory>
# CGI-BIN
ScriptAlias /lpar2rrd-cgi/ "/home/lpar2rrd/lpar2rrd/lpar2rrd-cgi/"
<Directory "/home/lpar2rrd/lpar2rrd/lpar2rrd-cgi">
    AllowOverride AuthConfig
    SetHandler cgi-script
    Options ExecCGI FollowSymLinks
    Require all granted
</Directory>

  • Linux Debian, Ubuntu : Apache2 (2.4+)


    Enable CGI-BIN and optionally even SSL if it is required 
    # a2enmod cgi
# a2enmod ssl
    Append this at the end of /etc/apache2/apache2.conf 
    # vi /etc/apache2/apache2.conf

AddHandler cgi-script .sh
Alias /lpar2rrd  "/home/lpar2rrd/lpar2rrd/www/"
<Directory "/home/lpar2rrd/lpar2rrd/www/">
    Options Indexes FollowSymLinks 
    Require all granted
</Directory>
# CGI-BIN
ScriptAlias /lpar2rrd-cgi/ "/home/lpar2rrd/lpar2rrd/lpar2rrd-cgi/"
<Directory "/home/lpar2rrd/lpar2rrd/lpar2rrd-cgi">
    AllowOverride None
    Options +ExecCGI +SymLinksIfOwnerMatch
    Require all granted
    SetHandler cgi-script
</Directory>

  • Apache 2.4+ generally


    Configure httpd.conf, it might be in different locations (depends of distribution)
    • /etc/httpd/httpd.conf
    • /etc/httpd/conf/httpd.conf
    • /etc/apache2/apache2.conf

    1. Verify alias_module and cgi_module is loaded (uncommented it, the path can be different) 
      LoadModule alias_module /opt/freeware/lib/httpd/modules/mod_alias.so
LoadModule cgi_module /opt/freeware/lib/httpd/modules/mod_cgi.so
    2. cgi_module could depend on mpm_prefork_module like here.
      Allow it as well (uncomment it) and disable mpm_worker_module, mpm_event_module 
      LoadModule mpm_prefork_module /opt/freeware/lib/httpd/modules/mod_mpm_prefork.so
# LoadModule mpm_worker_module /opt/freeware/lib/httpd/modules/mod_mpm_worker.so
# LoadModule mpm_event_module modules/mod_mpm_event.so
<IfModule mpm_prefork_module>
     LoadModule cgi_module /opt/freeware/lib/httpd/modules/mod_cgi.so
</IfModule>
    3. Append this at the end of httpd.conf 
      AddHandler cgi-script .sh
Alias /lpar2rrd  "/home/lpar2rrd/lpar2rrd/www/"
<Directory "/home/lpar2rrd/lpar2rrd/www/">
    Options Indexes FollowSymLinks 
    Require all granted
</Directory>
# CGI-BIN
ScriptAlias /lpar2rrd-cgi/ "/home/lpar2rrd/lpar2rrd/lpar2rrd-cgi/"
<Directory "/home/lpar2rrd/lpar2rrd/lpar2rrd-cgi">
    AllowOverride None
    SetHandler cgi-script
    Options ExecCGI FollowSymLinks
    Require all granted
</Directory>
      Sometimes appears necessary to remove "Require all granted" lines in both directives.

  • Apache 1.3 - 2.3


    Configure httpd.conf, it might be in different locations (depends of distribution)
    • /etc/httpd/httpd.conf
    • /etc/httpd/conf/httpd.conf

    # vi /etc/opt/freeware/apache/httpd.conf

Alias /lpar2rrd  "/home/lpar2rrd/lpar2rrd/www/"
<Directory "/home/lpar2rrd/lpar2rrd/www/">
    Options Indexes FollowSymLinks 
    Order allow,deny
    Allow from all
</Directory>
# CGI-BIN
ScriptAlias /lpar2rrd-cgi/ "/home/lpar2rrd/lpar2rrd/lpar2rrd-cgi/"
<Directory "/home/lpar2rrd/lpar2rrd/lpar2rrd-cgi">
    AllowOverride None
    Options ExecCGI FollowSymLinks
    Order allow,deny
    Allow from all
</Directory>

  • SELinux changes


    You need to disable the SELinux service protection to be able to utilize basic web services.
    You must do it in case you get "(13)Permission denied:" in Apache error_log.
    You have 2 options:

    • Disable SELinux only for Apache 
      Step 1. Query for the Boolean value you need to change:
# getsebool -a | grep httpd_dis
  httpd_disable_trans --> off

Step 2. Disable the SELinux protection:
# setsebool -P httpd_disable_trans=1

Step 3. Verify that the Boolean has changed:
# getsebool -a | grep httpd_dis
  httpd_disable_trans --> on
    • Globally disable SELinux 
      # setenforce Permissive
# vi /etc/sysconfig/selinux
  SELINUX=disabled
    Follow SELinux configuration in case you want to enable SELinux with our tools

Skip it in case of configuring Virtual Appliance

Install LPAR2RRD server

  • Download the latest LPAR2RRD server
    Upgrade your already running LPAR2RRD instance.

  • Install it: 
    # su - lpar2rrd
$ tar xvf lpar2rrd-7.XX.tar
$ cd lpar2rrd-7.XX
$ ./install.sh
$ cd /home/lpar2rrd/lpar2rrd
  • Schedule to run it from lpar2rrd crontab (it might already exist there)
    $ crontab -l | grep load.sh
$
    Add if it does not exist as above 
    $ crontab -e

# LPAR2RRD UI
0,30 * * * * /home/lpar2rrd/lpar2rrd/load.sh > /home/lpar2rrd/lpar2rrd/load.out 2>&1
    Assure there is just one such entry in crontab.

  • You might need to add lpar2rrd user into /var/adm/cron/cron.allow (/etc/cron.allow on CentOS 8) if crontab command fails
    Allow it for lpar2rrd user as root user. 
    # echo "lpar2rrd" >> /var/adm/cron/cron.allow
  • Initial start from cmd line: 
    $ cd /home/lpar2rrd/lpar2rrd
$ ./load.sh
  • Go to the web UI: http://<your web server>/lpar2rrd/
    Use Ctrl-F5 to refresh the web browser cache.

Troubleshooting

  • If you have any problems with the UI then check:
    (note that the path to Apache logs might be different, search apache logs in /var) 
    tail /var/log/httpd/error_log             # Apache error log
tail /var/log/httpd/access_log            # Apache access log
tail /var/tmp/lpar2rrd-realt-error.log    # STOR2RRD CGI-BIN log
tail /var/tmp/systemd-private*/tmp/lpar2rrd-realt-error.log # STOR2RRD CGI-BIN log when Linux has enabled private temp
  • Test of CGI-BIN setup 
    umask 022
cd /home/lpar2rrd/lpar2rrd/
cp bin/test-healthcheck-cgi.sh lpar2rrd-cgi/
    go to the web browser: http://<your web server>/lpar2rrd/test.html
    You should see your Apache, LPAR2RRD, and Operating System variables, if not, then check Apache logs for connected errors
Deploy the OS agent on each monitored server, no matter whether stand-alone, or virtualized.
The agent is written in Perl and calls basic OS commands to obtain required statistics like vmstat, iostat.

Additional information about the OS agent:

Prerequisites

  • Perl
  • Opened TCP communication between each Linux and LPAR2RRD server on port 8162. Connections are initiated from Linux side.
  • Additional disk space on LPAR2RRD server (about 40MB per each monitored Linux)
  • Create preferable dedicated user lpar2rrd on each Linux with minimum rights 
    # useradd -c "LPAR2RRD agent user" -m lpar2rrd

OS agent installation

  • Get the latest OS agent from download page

  • Linux installation under root
    # rpm -Uvh lpar2rrd-agent-6.00-0.noarch.rpm
# rpm -qa|grep lpar2rrd-agent
  lpar2rrd-agent-6.00-0
  • Linux Debian 
    # apt-get install lpar2rrd-agent_6.00-0_all.deb
  lpar2rrd-agent-6.00-0
  • Schedule its run every minute from the crontab on every Linux.
    This line must be placed into crontab for the lpar2rrd user (or any other user, preferably unprivileged): 
    # su - lpar2rrd
$ crontab -e 
* * * * * /usr/bin/perl /opt/lpar2rrd-agent/lpar2rrd-agent.pl <LPAR2RRD-SERVER> > /var/tmp/lpar2rrd-agent.out 2>&1
    Replace <LPAR2RRD-SERVER> by hostname of your LPAR2RRD server.

  • You might need to add lpar2rrd user into /var/adm/cron/cron.allow under root user if above "crontab -e" fails. 
    # echo "lpar2rrd" >> /var/adm/cron/cron.allow
  • The Linux host will appear in the LPAR2RRD server UI in the "Linux" folder one hour later, use Ctrl-F5 to refresh your web browser.

Troubleshooting

  • Client (agent) side:
    • Test if communication through the LAN is allowed. 
      $ telnet  <LPAR2RRD-SERVER> 8162
  Connected to 192.168.1.1   .
  Escape character is '^]'.
      This is ok, exit either Ctrl-C or ^].

    • Check following agent files:
      data store: /var/tmp/lpar2rrd-agent-*.txt
      error log: /var/tmp/lpar2rrd-agent-*.err
      output log: /var/tmp/lpar2rrd-agent.out

    • run the agent from cmd line: 
      $ /usr/bin/perl /opt/lpar2rrd-agent/lpar2rrd-agent.pl -d <LPAR2RRD-SERVER>
  ...
  Agent send     : yes : forced by -d 
  Agent send slp: sending wait: 4
  OS agent working for server: <LPAR2RRD-SERVER>
  store file for sending is /var/tmp/lpar2rrd-agent-<LPAR2RRD-SERVER>-lpar2rrd.txt
      It means that data has been sent to the server, all is fine
      Here is example when the agent is not able to sent data : 
      $ /usr/bin/perl /opt/lpar2rrd-agent/lpar2rrd-agent.pl -d <LPAR2RRD-SERVER>
  ...
  Agent send     : yes : forced by -d 
  Agent send slp: sending wait: 1
  OS agent working for server: <LPAR2RRD-SERVER>
  store file for sending is /var/tmp/lpar2rrd-agent-<LPAR2RRD-SERVER>-lpar2rrd.txt
  Agent timed out after : 50 seconds /opt/lpar2rrd-agent/lpar2rrd-agent.pl:265
      It means that the agent could not contact the server.
      Check communication, port, above telnet example, DNS resolution of the server etc.

  • Server side:
    • test if the daemon on LPAR2RRD server is running, and checking the logs 
      $ ps -ef|grep lpar2rrd-daemon
  lpar2rrd 10617010 1 0 Mar 16 - 0:00 /usr/bin/perl -w /home/lpar2rrd/lpar2rrd/bin/lpar2rrd-daemon.pl
$ cd /home/lpar2rrd/lpar2rrd
$ tail logs/error.log-daemon
$ tail logs/daemon.out
  new server has been found and registered: Linux (lpar=linuxhost01)
  mkdir : /lpar2rrd/data/Linux/no_hmc/linuxhost01/
      It means that new OS agent has been registered from linuxhost01 (Linux stand-alone example)

    • Test if OS agent data is being stored on the LPAR2RRD server and have a current timestamp: 
      $ cd /home/lpar2rrd/lpar2rrd
$ ls -l data/<server name>/*/<Linux name>/*mmm
  -rw-r--r-- 2 lpar2rrd staff  7193736 Mar 17 16:16 data/<server name>/no_hmc/<Linux name>/cpu.mmm
  -rw-r--r-- 2 lpar2rrd staff  7193736 Mar 17 16:16 data/<server name>/no_hmc/<Linux name>/lan-en1.mmm
  -rw-r--r-- 2 lpar2rrd staff 10790264 Mar 17 16:16 data/<server name>/no_hmc/<Linux name>/mem.mmm
  -rw-r--r-- 2 lpar2rrd staff  7193736 Mar 17 16:16 data/<server name>/no_hmc/<Linux name>/pgs.mmm
  -rw-r--r-- 2 lpar2rrd staff  7193736 Mar 17 16:16 data/<server name>/no_hmc/<Linux name>/san-vscsi0.mmm
  -rw-r--r-- 2 lpar2rrd staff  3597208 Mar 17 16:16 data/<server name>/no_hmc/<Linux name>/san_resp-vscsi0.mmm
$ find data -name mem.mmm -exec ls -l {} \;
  ...
  • In case of a problem check our forum or contact us via support@lpar2rrd.com.
    We would need this data for start of troubleshooting.