Book Image

Red Hat Enterprise Linux 8 Essentials

By : Neil Smyth
1 (1)
Book Image

Red Hat Enterprise Linux 8 Essentials

1 (1)
By: Neil Smyth

Overview of this book

Red Hat Enterprise Linux 8 is one of the most secure and dependable operating systems available. For this reason, the ambitious system or network engineer will find a working knowledge of Red Hat Enterprise 8 to be an invaluable advantage in their respective fields. This book, now updated for RHEL 8.1, begins with a history of Red Enterprise Linux and its installation. You will be virtually perform remote system administration tasks with cockpit web interface and write shell scripts to maintain server-based systems without desktop installation. Then, you will set up a firewall system using a secure shell and enable remote access to Gnome desktop environment with virtual network computing (VNC). You’ll share files between the Red Hat Enterprise Linux 8 (RHEL 8) and Windows System using Samba client and NFS. You will also run multiple guest operating systems using virtualization and Linux containers, and host websites using RHEL 8 by installing an Apache web server. Finally, you will create logical disks using logical volume management and implement swap space to maintain the performance of a RHEL 8 system. By the end of this book, you will be armed with the skills and knowledge to install the RHEL 8 operating system and use it expertly.
Table of Contents (32 chapters)
32
Index

7.20 Enabling Stored Metrics

In a standard installation Cockpit does not retain any of the performance metric data beyond what is displayed in the short time window covered by the graphs. To retain the data collected by Cockpit, the stored metrics feature needs to be installed. Begin by installing the cockpit-pcp package as follows:

# dnf install cockpit-pcp

To enable metric persistence, display the System screen and click on the Enable stored metrics... link highlighted in Figure 7-22:

Figure 7-22

Once this option has been selected, Cockpit will request permission to install the cockpit-pcp, pcp-libs and pcp-selinux packages. Once these packages have been installed, the Enable persistent metrics link will have been replaced by a control labeled Store Metrics. When this option is enabled, the performance graphs will include additional controls allowing you to move back and forth in time to view historical data and to change the data time frame ranging from 1 hour up...