OP5 Monitor - How to manage your operating system when running OP5 Monitor (EL7).

# nmtui

# systemctl enable NetworkManager --now 

NTP (Network Time Protocol)

Your OP5 Monitor System should use a Network Time Server. Ensuring that the system time is correct is crucial for many reasons, not only for the product itself but also for things like comparing logs across systems. You may add several server entries for reduncancy. If you are unsure about whether you have an NTP server to synchronize against you can always use pool.ntp.org which is a large pool of free to use NTP servers on the Internet.

NTP on RHEL 7

In EL7, Chronyd is used instead of ntpd by default. Ntpd was used on EL6, and also works for EL7 if you prefer it. Basic configuration for Chronyd is available in:

/etc/chrony.conf

Use "chronyc" to inspect the state of chronyd. Verify your current time with the "tracking" command:

# chronyc tracking

Check your current sources with the "sources" command, add -v for an explanation of the symbols:

# chronyc sources -v

The service name for stopping, checking status and so forth is "chronyd":

# systemctl status chronyd

You can check your current time zone and verify that it is correct with:

# timedatectl
Local time: Fri 2018-09-14 10:54:38 CEST
Universal time: Fri 2018-09-14 08:54:38 UTC
(...)

If it needs to be adjusted, you can find your timezone with:

# timedatectl list-timezones 

and set it accordingly:

# timedatectl set-timezone Europe/Stockholm

You may also want to verify the time zone used by PHP, as this is set separately and may affect things like reports in the web GUI. This is set in:

/etc/php.d/00_op5_timezone.ini

Example:

# cat /etc/php.d/00_op5_timezone.ini
date.timezone = Europe/Stockholm

If you are using ntpd

The service name is "ntpd"

# systemctl status ntpd

Check whether it works correctly:

# ntpstat

Configuration is available for ntpd is available in:

/etc/ntp.conf

Configuring Postfix to modify the e-mail notification sender

By default, your notifications will be sent from:

op5Monitor@hostname.localdomain

You may want to change this in Postfix.

From the Postfix documentation:

The myorigin parameter specifies the domain that appears in mail that is posted on this machine. The default is to use the local machine name, $myhostname, which defaults to the name of the machine. Unless you are running a really small site, you probably want to change that into $mydomain, which defaults to the parent domain of the machine name.

Example:

# echo "myorigin = test.com" >> /etc/postfix/main.cf

Or, to run it on all nodes and then restart Postfix on all nodes:

# mon node ctrl --all --self -- 'echo "myorigin = test.com" >> /etc/postfix/main.cf && systemctl restart postfix && echo "Config updated, Postfix restarted."'

This will result in e-mails appearing to come from "op5monitor@test.com" instead.

Scheduling a run of op5-backup via cron

For more information on how to run op5-backup, please see:

# op5-backup -h

When you have a command that you are happy with, schedule this command via cron. For more information on cron, please see "Automating System Tasks" of the RHEL 7 documentation. In this example, we will schedule a backup job.

Run the following command as root:

# crontab -e

Add the following line and save the file:

30 01 * * * root /usr/sbin/op5-backup >/dev/null 2>&1

Your backup will now run daily at 1:30 AM and will place the file in /root by default

Configuring network settings 

Network settings on RHEL 7

You may have to install nmtui:

# yum install NetworkManager-tui

When installed, simply run:

# nmtui

From the RHEL 7 documentation:

The NetworkManager text user interface (TUI) tool, nmtui, provides a text interface to configure networking by controlling NetworkManager ... to navigate, use the arrow keys or press Tab to step forwards and press Shift+Tab to step back through the options. Press Enter to select an option. The Space bar toggles the status of a check box.

For more information on how to use nmtui, or nmcli, please see "Configuring IP Networking" of the RHEL 7 documentation. 

Updating the operating system, and Monitor, with yum

For more information on how to use yum, please see "Yum" of the RHEL 7 documentation.

To simply see what packages have updates available, run:

# yum check-update

To update all packages, run:

# yum update

Yum will ask for confirmation before starting the update.

Handling services on RHEL 7

For more information, see "Managing Services with systemd" in the RHEL 7 documentation.

In addition to using commands like "mon stop" and "mon start", you can stop and start services using systemctl. For example, after changing PHP settings, you will probably want to restart httpd:

# systemctl restart httpd

Verify status:

# systemctl status httpd

Installing a license

See Adding a license.