Click storage Live CD/DVD and lick the optical drive image and choose the same iso image you built the system with. Press okay. I needed to reboot to make the dvd visibl. Your mileage may vary. Click back into the system and log in to system as student I usually arrange the desktop at this […]
Read More →Author: Steven Protter
Building a RHCSA classroom server (part 1)
This article shows how to build the classroom server which most RHCSA test exercises are run against. The environment is virtual box running on a very new Macbook Pro with a modern CPU and 32 GB of Ram. We start with a dead machine transferred from the old Mac. Next we add in the CentOS […]
Read More →RHCSA exam prep recover root password
Your root password is lost and gone forever. Temporary video version without sound.[youtube][/youtube] Your sudo account has been blocked by an incompetent SA(System Administrator). This according to reports is often on the test. It takes 5 minutes to fix. Reboot your system and intervene on the kernel prompt. Press e to edit go down to […]
Read More →The firewall project
Converting a fairly elaborate iptables based firewall with proprietary anti-spam scripts to the modern firewall-command architecture without revealing any IP. First lets take a look where we started: [root@instance-5 ~]# systemctl list-unit-files | egrep “iptables|firewall” firewalld.service masked iptables.service disabled This shows iptables as disabled but a […]
Read More →We’re going to be studying together for the RHCSA
My current employer is under requirement that all on site system administrators be Red Hat Certified. That is actually the reason why I took the RHC in 2006. My employer the time NDS on Har Hoztvim Israel wanted the people supporting customers to have certification. The test they chose was the RHCE. As those […]
Read More →Maria-db(mysql) two node installation with galera data replication
This is the first step toward unsupported installation of the NDC, New Data Cloud. To get the commercial version with full support, click here. This document takes you through the installation and creation of a two node database installation. This install was done in google compute engine but with the right band width will work […]
Read More →Use TCP wrappers with care
Real life story. DMZ based server dedicated to SFTP was configured with sshd rules in /etc/hosts.allow sshd : ALL@16.89.97.*:ALLOW sshd : ALL@14.251.*:ALLOW sshd : AAL@208.94.61.*:ALLOW Should have been: sshd : ALL@16.89.97.*:ALLOW sshd : ALL@14.251.*:ALLOW sshd : ALL@208.94.61.*:ALLOW That network was the firewall to the outside world. The end users were inconvenienced and the firewall […]
Read More →Quick and dirty autofs script share
I run a large unix and linux server farm on the west coast. In the old days we had problems with scrip versions. The problem was we pushed scripts from a central server and inevitably due to network or space issues the updates did not happen reliably. In 2012 we opened up our unix management […]
Read More →Making sure what is configured to mount is mounted
Here is a script that uses some advanced awk commands to check that what is configured to be mounted in /etc/fstab is actually mounted. #!/bin/ksh ######################################################################### # fsrootreserve #HPUX_SCRIPTS=/opt/depots/scripts/system_build/HPUX #COMMON=/opt/depots/scripts/system_build/COMMON # Load common environment . /opt/scripts/env/.scriptenv.linux # set total variable for reserve blocks tot=0 echo “. Checking mount status of all […]
Read More →Network install point httpd with Centos or RHEL6 using kickstart
Why set up a network install point? So you can do consistent Linux installations. Really so you can do the same installation over and over again and come out with consistent results. Today’s article is how to set up the install point and have it work. There is credit for the source article below but […]
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