Book Image

Red Hat Enterprise Linux Troubleshooting Guide

By : Benjamin Cane
Book Image

Red Hat Enterprise Linux Troubleshooting Guide

By: Benjamin Cane

Overview of this book

Red Hat Enterprise Linux is an operating system that allows you to modernize your infrastructure, boost efficiency through virtualization, and finally prepare your data center for an open, hybrid cloud IT architecture. It provides the stability to take on today's challenges and the flexibility to adapt to tomorrow's demands. In this book, you begin with simple troubleshooting best practices and get an overview of the Linux commands used for troubleshooting. The book will cover the troubleshooting methods for web applications and services such as Apache and MySQL. Then, you will learn to identify system performance bottlenecks and troubleshoot network issues; all while learning about vital troubleshooting steps such as understanding the problem statement, establishing a hypothesis, and understanding trial, error, and documentation. Next, the book will show you how to capture and analyze network traffic, use advanced system troubleshooting tools such as strace, tcpdump & dmesg, and discover common issues with system defaults. Finally, the book will take you through a detailed root cause analysis of an unexpected reboot where you will learn to recover a downed system.
Table of Contents (19 chapters)
Red Hat Enterprise Linux Troubleshooting Guide
About the Author
About the Reviewers

Making mounts permanent

Currently, even though we mounted the NFS share with the mount command, this mounted filesystem is not considered persistent. The next time this system reboots, the NFS mount will not be remounted.

That is because as a system boots up, part of the boot process is to read the /etc/fstab file and mount any filesystems defined within it.

To better understand how this works, let's look at the /etc/fstab file on the database server:

[db]# cat /etc/fstab

# /etc/fstab
# Created by anaconda on Mon Jul 21 23:35:56 2014
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
/dev/mapper/os-root /                       xfs     defaults        1 1
UUID=be76ec1d-686d-44a0-9411-b36931ee239b /boot                   xfs     defaults        1 2
/dev/mapper/os-swap swap                    swap    defaults        0 0  /data      nfs  defaults  0 0

The contents of the...