Linux

Linux Servers and Advanced System Administration class scheduled for June 10 – 14

April 22, 2013
Announcements Linux Millennium Technology Consulting LLC Training

Millennium Technology Consulting LLC has scheduled its course, Linux Servers and Advanced System Administration for June 10 – 14, 2013.

This unique 5-day class, entitled, Linux Servers and Advanced System Administration covers a wide range of advanced topics in a manner never seen in other courses.

The topics covered in this course are:

 Administrative Tools  WordPress and MySQL
 IPTables  MailMan
BIND DNS  VNC
DHCP  NFS
Network Configuration  SAMBA
SSH  NTP
SendMail  CUPS
SpamAssassin  SELinux
MIMEDefang  Building RPMs
Apache Web Server

But it is how the class is structured as much as the specific subjects covered that makes it unique. Most classes that cover these subjects do not cover all of them, and they do not treat them as a part of an integrated whole system. The Linux Servers and Advanced System Administration class treats these as parts of a unified whole

By the end of the class each student will have a fully working Linux system with a firewall; a name server with forward and reverse zones; a DHCP server; an email server with integrated anti-spam; two working web sites with one a static HTML site and the other a complete WordPress site with a MySQL back end; A MailMan mailing list server; A VNC server; NFS and Samba shares. The student will also learn to build RPM packages.

In addition, students will learn advanced aspects of some of the system commands covered in my Theory and Practice of Linux System Administration course, as well as some interesting new commands that can be used for advanced system administration tasks and problem determination.

Linux Servers and Advanced System Administration – Seats for this 5-day course are available and cost $2995.00. Please contact us to sign up for classes as soon as possible. Our classroom facilities are very limited so class sizes are very small.

 

More about Fedora 18

February 23, 2013
Information Linux Reviews Technical Tips and Tricks

In my review of Fedora 18, I discussed my initial impressions of that newest release. Having now begun to install Fedora 18 on several more hosts in my constantly changing world I have found some interesting under the cover changes.

firewalld

A new firewall, firewalld, is now the default firewall for Fedora. Of course Fedora is the proving ground for many new things so, while this change was not particularly well documented, changes to Fedora in general should not be a surprise. The firewalld daemon is mentioned in three short paragraphs in the Fedora 18 release notes which only references the man pages for the new firewalld commands for further information, and once as being a new addition in the Technical Notes document. Both are available as PDF files from the Fedora Documentation Project.

The firewalld rules are quite complex compared to what I have been using with IPTables. This, and the fact that I am not yet familiar with the rule syntax or the overall structure of firewalld means that, for now at least, I need to revert to IPTables on my Fedora 18 hosts.

Reverting to IPTables

The good news is that the old IPTables firewall is still available until I can learn how to best create the firewall rules I need with firewalld. However it, too, has changed and some of the old IPTables rules, especially those using state related rule sets have been altered.

First, to convert back to IPTables, stop and disable the firewalld service and start and enable the iptables service.  Of course you must do this safely with your network disabled until you can get your new (old) firewall back in place. Then use the iptables-restore command to restore your old IPTables rules from the saved copy. You did save a backup copy of your IPTables firewall rules, right?

At this point, IPTables gives some errors indicating that one should use new connection tracking rules in lieu of the state-related rules. The best part is that IPTables is smart enough to give you the warning message and then translate the rules into connection tracking rules. At that point you can simply use the iptables-save command view the translated rules and redirect the output to /etc/sysconfig/iptables to save the translated rules.

So now I will take some time to learn this new firewall system while my IPTables firewall protects me.

Here is a link to the Fedora Project FirewallD documentation. http://fedoraproject.org/wiki/FirewallD

Millennium Technology Consulting LLC Adds “Introduction to Linux” Class

February 14, 2013
Announcements Linux Millennium Technology Consulting LLC Training

Millennium Technology Consulting LLC announces the availability of the newest class in its training line-up.

The Introduction to Linux course provides a two-day survey of various aspects of using Linux with both the desktop and the command line interface (CLI). It is an introduction to Linux for someone who intends to be more than a casual user of Linux and covers some basic non-privileged administrative tasks. It also introduces a few of the basic concepts and some of the basic tools used by the root user.

View the Introduction to Linux course page on the Millennium Technology Consulting LLC web site for additional details about this course.

“Linux Servers and Advanced System Administration” Class Status

October 6, 2012
Linux Millennium Technology Consulting LLC News Training

The advanced class I have been working on for over a year is nearly ready. This unique class, entitled, Linux Servers and Advanced System Administration covers a wide range of advanced topics in a manner never seen in other courses.

The topics covered in this course (still subject to change) will be:

 Administrative Tools  WordPress and MySQL
 IPTables  MailMan
BIND DNS  VNC
DHCP  NFS
Network Configuration  SAMBA
SSH  NTP
SendMail  CUPS
SpamAssassin  SELinux
MIMEDefang  Building RPMs
Apache Web Server

But it is how the class is structured as much as the specific subjects covered that makes it unique. Most classes that cover these subjects do not cover all of them, and they do not treat them as a part of an integrated whole system. The Linux Servers and Advanced System Administration class treats these as parts of a unified whole

By the end of the class each student will have a fully working Linux system with a firewall; a name server with forward and reverse zones; a DHCP server; an email server with integrated anti-spam; two working web sites with one a static HTML site and the other a complete WordPress site with a MySQL back end; A MailMan mailing list server; A VNC server; NFS and Samba shares. The student will also learn to build RPM packages.

In addition, students will learn advanced aspects of some of the system commands covered in my Theory and Practice of Linux System Administration course, as well as some interesting new commands that can be used for advanced system administration tasks and problem determination.

I expect this course to be ready for a test class in December of 2012. It will be held in my Raleigh, NC, training facility. The exact date is still a bit uncertain but, at this time, I expect it to be the first week of December.

The class will normally cost $2995. There will be discounts available for that session because it will be a test class. As always, the additional $500 discount for TriLUG members will apply. Please contact Millennium Technology Consulting LLC for details.

Fedora 17 Released

May 30, 2012
Linux News

Fedora 17, the latest in a long series of Fedora Linux releases, was released on Tuesday, May 29. Code named “Beefy Miracle,” it offers many new features and upgrades.

I have already installed it on my primary workstation which I don’t recommend for most people to do on day 1 of any release. I also installed Fedora 17 onto a VirtualBox VM where I will do my best to break it. Hopefully it will not break my primary workstation.

Here are a few of my first impressions.

In Brief

I have already noticed significant speed improvements over Fedora 16 and previous releases. KDE screen animations and effects are enabled by default, possibly as a result of the speed gains, and they make for a fun desktop. Perhaps the new 6.3.3 kernel is at least in part responsible for the speed gains.

The BTRFS filesystem is no longer an option during installation, but can be used on partitions formatted after installation. This is due to issues with the filesystem. I have also had problems in the recent past with installations using EXT4 so I personally do not use that for the main installation.

I had problems with the upgrade from DVD so had to do a complete installation. I was able to save my home filesystem and restored other critical data from backups so it was not a major issue. I always expect problems with upgrades and new installations, so no real surprise there. I think the issues may be due to the non-Fedora repositories I have configured, but I need to experiment more with that.

In general everything seems to be working well so I am happy.

I will write a more compete review as soon as I have more experience with this release.

 

Install Issues with Fedora 16 and EXT4 Filesystem

May 20, 2012
Information Linux Technical

I just had an interesting experience while installing Fedora 16 on my primary workstation. It took me about 3 days and many attempted installations to figure this out. This is not a review, just a bit about my experience.

At first I wiped out my hard drive entirely since it has been several years since I did a really clean installation. That is, a complete wipe out of my hard drives—after first making certain that I had multiple good backups. Over time much cruft can accumulate from old application configuration and data and I wanted to get rid of everything except data I really wanted to keep.

Symptoms

The initial installation of Fedora 16 appeared to go well using the default choice of EXT4 for the filesystem type. After starting to make configuration changes and restoring a few directories in my non-root user home directory, KDE started crashing on a regular basis. It would indicate problems with Segment Faults. This is not good and can mean many bad things.

After installing several times with similar results, I decided to go back to Fedora 15. During the installation, I used EXT3. I had previously experienced an occasional problem with Fedora 15 while using EXT4, but nothing particularly repeatable. Many of the problems were during installation using EXT4 and I would get errors indicating that a specific package was not able to be installed. Looking at the log terminal (Ctrl-Alt-F3) most errors appeared to be on the DVD, but the DVD always tested as having no defects at the beginning of the installation.

Solution

My decision to use EXT3 was kind of on a whim, but the next install went without problems and I had no problems doing basic configuration. So I decided to reinstall Fedora 16 using EXT3 instead of EXT4 and have had no problems since. This is using the same physical hardware and the exact same partitions and logical volumes.

I think this indicates, at least to me, that there are still some bugs in EXT4. I have not however, seen this problem on some of my other systems. Perhaps it is the larger 1.5TB drives I am using on this system.

I hope this helps by preventing you from spending 3 days to discover and resolve this problem.