08. January 2015 · Comments Off on Maintenance outages today, January 08, 2014 · Categories: Announcements, News, Site Outage

I will be performing some emergency maintenance today, to replace a couple old and failing UPS units. The batteries are OK, but the units themselves are failing after several years.

There will be a few short outages of the email and web sites during this maintenance.

Thanks for your patience.

David Both


08. July 2014 · Comments Off on It helps to know how things work · Categories: Linux, Opinion, Technical, Training

It really helps to know how things work when it becomes necessary to fix them.

This was true when I was fixing audio equipment in the early ’70s, and supporting computers and software for IBM, MCI, Interpath, and Cisco over the years, and teaching Linux for Red Hat and my own company, Millennium Technology Consulting LLC. The intimate knowledge of how Linux works has also been invaluable since I started working with it in about 1996.

Unless you know how things really work, there is a tendency to use a shotgun approach to problem solving. That wastes time and, if replacing parts is involved or purchasing new software, can be quite expensive.

After all, would you be willing to pay for the auto mechanic to replace several perfectly good parts while trying to find the one part actually causing the problem – and to pay him for time and materials as well? Of course not. Although that used to be the case more often than it should have been.

I submit for your approval a problem I just fixed this morning – with this web site.

It was not a problem that affected the external operation of the DataBook web site, but I could no longer use any editor from within WordPress to edit pages and posts such as this one.

Because I know several important things about WordPress I was able to think about the problem and correct it on the first try. I know the following about WordPress:

  • The data for WordPress web sites is stored separately in a MySQL database. Separation of data and code is always a good thing to do.
  • There is one and only one, small site configuration file for each WordPress web site, wp-config.php.
  • All WordPress plugins, themes, and uploaded graphics also have their own directories.
  • The Apache web configuration is separate from the WordPress site configuration.

So it was a simple matter to simply delete the entire directory in which the WordPress instance was installed for that web site. Everything.

I then copied the entire directory structure from a known working web site to replace the one I deleted. I then copied the original wp-config.php to the appropriate location in the newly copied WordPress directory structure and my web site was up and running again. It was then trivial to copy from backups the rest of the plugins and graphics to complete the process. All in all it took less than 5 minutes.

Not having the understanding I do of how WordPress, MySQL and Apache work together to produce a web site, I would have been tempted to simply delete everything in the WordPress directory (/var/www) for that web site and start over by reinstalling WordPress and configuring it from scratch. As easy as that is for WordPress, it would still have taken much longer than it did for me to actually fix the problem.

If I had understood more about the PHP coding of WordPress itself, I probably could have simply repaired the offending file that was likely corrupted for some reason. But that would probably taken much longer in any event.

If you are interested in learning how Linux works so that you can identify, understand and fix problems in the most effective ways, try the Linux classes I offer at Millennium Technology Consulting LLC.


07. July 2014 · Comments Off on CentOS 7.0 released · Categories: Linux, News · Tags: , , ,

CentOS 7 was released today, July 7.

CentOS is identical to Red Hat Enterprise Linux (RHEL) with the only exception being the branding text and graphics. CentOS is a fully supported Community ENTerprise Operating System that provides free upgrades and support.

CentOS 7 incorporates several major changes and enhancements. These includes things like systemd and GNOME 3. In addition, the XFS file system is now the default.

Many of the new features in CentOS, such as systemd, have been around for a couple years, most notably in the Fedora distribution. Fedora is the upstream feeder to RHEL and many new RHEL features are first introduced in Fedora.

See http://www.centos.org/ for more details anout CentOS 7.


22. April 2014 · Comments Off on David Both to present “SystemV Startup vs systemd” at TriLUG on May 8 · Categories: Announcements, News

I will be giving a presentation, “SystemV Startup vs systemd” at the TrilUG meeting on Thursday, May 8.

Topic: SystemD
Presenter: David Both
When: Thursday, 8th May 2014, 7pm (pizza from 6.45pm)
Where: NC State Engineering Building II Room 1021, Centennial Campus
Parking: The parking decks and Oval Drive street parking are free after 5pm
Website: http://trilug.org/2014-05-08/systemd

The new systemd daemon replaces the init process for some distributions already and is coming to many more. systemd provides service management and much more as well as startup for services designated to run on startup. It is designed to increase startup speeds as well as to conserve system resources by using a new startup strategy in which services are not started until they are actually required. This presentation will briefly review the Linux boot process and the old SystemV startup process. It will then discuss in more detail the startup process using systemd, and the reasons for creating the new systemd daemon and some of the advantages it provides. We will also discuss configuration files and some of the more common commands required to cause systemd to do our bidding. Backward compatibility will also be covered.

I hope to see you there.


11. April 2014 · Comments Off on Dealing with the HeartBleed bug · Categories: News, Security

It has been a very hectic couple days since I woke up Tuesday morning to the news about the so-called HeartBleed bug. I spent a good bit of time Tuesday exploring the available information and then creating a program that would do much of the work required to actually fix the problem, and then testing my program. I spent a good deal of Wednesday fixing the problem on the computers for which I have some responsibility.

I have taken a bit of a breather after all that and here is my assessment.

HeartBleed is the most serious bug ever

HeartBleed is a bug that is both dangerous and insidious. If you have a computer that is on the Internet, you must assume that your data has been stolen. Even worse, you have no way to know who has been stealing your data or for how long; this bug opens up your data in such a way that no trace of the crime is left behind.

There is even a web site dedicated to HeartBleed, that provides the gory details about this bug and its effects that is strictly factual and contains none of the hype required by alleged news organizations that are primarily entertainment and not information – infotainment.  Unfortunately, in this case, most of the hype seems to be deserved.

What it does

The HeartBleed bug does nothing by itself. It simply provides an open door to crackers (black hat hackers) who use that door to steal personal data. HeartBleed affects the OpenSSL library of security programs that are used by most computer systems. The bug allows access to the memory of the affected server.

When your computer connects to a web site that uses encryption, such as your bank, the OpenSSL code is used for communicating between your computer and the bank’s computer. When there is no activity for a period of time, OpenSSL produces a heartbeat, a simple transmission of a packet of data that says “I am still here” to the server that prevents the server from closing the connection before you are finished with your business and the server responds with a simple acknowledgement of that “ping.”

The crackers can use this by faking a heartbeat signal from your computer. The acknowledgement is sent back to the cracker’s computer and the cracker can then request data from the memory of the server. The memory leaked to the cracker can contain any or all of your personal data stored on that site.

The affected computers are the servers that run most of the websites in the world and that contain your medical, personal and financial data including your social security numbers, banking information and everything else you don’t want the bad guys to have access to.

The worst part is that you do not have to do anything to have your data stolen except to visit a web site you already trust like your bank.

Recovery

Almost every version of the OpenSSL library has been fixed. And most of the large organizations that have servers, such as banks and other financial institutions, eCommerce websites like, hopefully, Amazon, Google and so on, have already patched their web sites.

The first thing you should do is install the latest updates to your own computer(s) regardless of which operating system you use. If your operating system is too old for new updates, such as Windows 95 or XP, or Fedora Linux 18 or earlier, upgrade your operating system and install all of the current updates. If you need to upgrade your computer in order to upgrade your operating system, then do so.

Second, change all of the passwords you use on web sites. ALL OF THEM!  All of your passwords have been compromised. If you continue to use them your data will be stolen.

The real problem is in knowing whether the web sites you use and which have some of your sensitive data have been fixed. By this morning, Thursday, April 10, many have some sort of notice on their login page. In most cases the ones I see seem to say that they never had a problem.  But you cannot count on that. Many are ignoring it entirely. Just do the best you can. Change all of your passwords anyway. If you learn later that the web site did not fix the vulnerability until after you had changed your password, change it again.

A few password guidelines:

  • Never use the same password on multiple web sites. Thus if one site is compromised, you won’t have to change all of your passwords.
  • Use long passwords that are at least 8 characters in length. This makes it much more difficult to guess or crack your password.
  • Passwords should contain a combination of lower and upper case letters, numbers, and special characters. This makes it much more difficult to guess or crack your password.
  • Never use the same password twice. An old password that was hacked, if used over, can still be used to attack your account.
  • Do not use birth dates, Social Security Numbers, pet, friend or spouse names, or dictionary words for your passwords. This will make it much more difficult to social engineer your passwords.
  • Change your passwords frequently. At least every 90 days, but once a month is even better. This will limit the time of your vulnerability if a site is compromised.
  • Never write down your passwords. Ever.

Good security is hard work

Yes, good security is hard work. That is why companies hire a lot of expensive people to handle it for them. For end users, it also takes time and some creativity to come up with reasonable passwords that are safe but which can also be remembered. It will be frustrating.

Bad security is an even bigger hassle. It can cost you your identity, lots of money and a great deal of time and frustration – far more than good security will cost.


09. April 2014 · Comments Off on FAQs about the HeartBleed vulnerability · Categories: Information, Security

I received this on the CentOS list. You might find it helpful.


Since this is the first post about the openssl update, I want to answer
a couple questions here:

1. The first susceptible version of openssl in a CentOS release was
openssl-1.0.1e-15.el6, released on December 1, 2013.

2. The version of openssl that you should install to fix the issue is
openssl-1.0.1e-16.el6_5.7, released on April 8, 2014.

3. Versions of CentOS-6.5 openssl that were affected are:
openssl-1.0.1e-15.el6, openssl-1.0.1e-16.el6_5,
openssl-1.0.1e-16.el6_5.1, openssl-1.0.1e-16.el6_5.4.

4. Only CentOS-6.5 was affected. CentOS-6 at versions 6.4 or earlier
was not affected. No versions of CentOS-5 (or any other CentOS) were
affected.

Besides doing updates, things you should do include:

1. Besides doing the updates, you should replace any certificates using
SSL or TLS that are openssl based. This includes VPN, HTTPD, etc. See
http://heartbleed.com/ for more info on impacted keys.

2. See this page for figuring out which services you should restart
after applying updates .. or just reboot the machine which will restart
all services:

https://access.redhat.com/site/solutions/781793


07. March 2014 · Comments Off on Free “Introduction to Linux” course from the Linux Foundation, edX, MIT and Harvard · Categories: Linux, News, Training

Free classes are always cool, especially in times when companies do not have big training budgets. And it seems like one of the best training opportunities in years is here.

Linux is hot as a job skill. The Linux Foundation’s 2014 Linux Jobs Report found that 90 percent of hiring managers are looking to hire Linux professionals in the next half-year. But demand is greater than supply. Not only is Linux hiring hot, but Linux professionals are also getting larger and more frequent pay raises.

The Linux Foundation along with edX and major educational institutions Harvard and MIT have combined to provide a Massive Open Online Course (MOOC), Introduction to Linux. This course is free of charge and you can take it to earn a certificate or you can audit the course if you cannot make the full time commitment.

The course will be available some time in the 3rd quarter of 2014. The folks at VentureBeat have a short writeup about this which sounds quite interesting. You can read about the course and register here. It is estimated that the time commitment if you take this course is 40 to 60 hours.

Now you might ask why, as a Linux trainer, I would suggest you take this course rather than mine? Well, free is free, right?

I do plan to take this class myself as there is always more to learn. I enjoy teaching my own two-day “Introduction to Linux” course, and I do get paid for it. So, again, why? Because I cannot imagine that anything done by the Linux Foundation and the combination of organizations that have put this course together would not be really, really good.

Opportunities like this do not come along frequently. Take advantage of it.


06. March 2014 · Comments Off on Linux Security Bug – Update · Categories: News, Security

The security bug is identified as CVE-2014-0092 now has fixes available for the following distributions of which I am certain.

  • CentOS
  • Debian
  • Fedora
  • Red Hat

Check your own distribution to verify the availability of the fix. Note that not all releases of these distros have a fix available yet. If your release does not have a fix for this bug you should seriously consider upgrading to a release that does.


05. March 2014 · Comments Off on Serious security bug found in Linux · Categories: News, Open Source Software, Security

A very serious bug has been found in the Open Source GnuTLS package. Many programs and the Linux operating system itself use this package to deal with the encryption of data streams. The bug was discovered during a routine code audit by Red Hat, and appears to be a simple error by a programmer. This is as opposed to the flaw intentionally inserted into the cryptography algorithm by the NSA to enable them to eavesdrop on encrypted communications. The NSA flaw does not affect Linux.

The fix is available and I have explicitly confirmed that it has been included in an update for GnuTLS on CentOS that was made available this morning. I have installed it on my server and firewall here which all use CentOS and ensured that nothing else obvious is broken. I have no idea whether this update requires a reboot, but I will reboot all of the affected CentOS systems after the updates have been installed.

This fix is not yet available for Fedora. Check the updates for your own distribution to verify whether this fix has been included or not.

Part of the news here is that serious security bugs in Linux, as this one is, are few and far between so it gets heavy media coverage. The other part of the news, and the part that will get little or no coverage, is that it is only because the code is Open Source that Red Hat could perform an audit and discover the problem. The open source aspect of this code is also the reason that the fix is available so quickly after the problem is discovered, and the ease with which I can confirm that it is included in the new version of the GnuTLS package by looking at the changelog.

The link below goes into more detail, if you are interested.

http://arstechnica.com/security/2014/03/critical-crypto-bug-leaves-linux-hundreds-of-apps-open-to-eavesdropping/#p3



29. January 2014 · Comments Off on Training Calendar set for first half of 2014 · Categories: Linux, News, Training · Tags: , ,

Millennium Technology Consulting LLC has finalized its class schedules for the first half of 2014.


Training Calendar for First Half of 2014
Course Date Availability
Theory and Practice of Linux System Administration February 24 – 28  Seats available
Linux Servers and Advanced System Administration March 17 – 21  Seats available
Theory and Practice of Linux System Administration March 31 – April 4  Seats available
Linux Servers and Advanced System Administration April 14 – 18  Seats available
Theory and Practice of Linux System Administration April 28 – May 2  Seats available
Theory and Practice of Linux System Administration May 19 – 23  Seats available

Theory and Practice of Linux System Administration

This course is intended for trainee or  junior Linux Systems Administrators who wish to advance their knowledge, and administrators of other Unix versions or Windows who wish to become Linux System Administrators. This class is heavily oriented towards hands-on activities. At least half of the class time is allotted to lab projects.

CentOS

This class is taught using CentOS because it is the downstream distribution of Red Hat Enterprise Linux (RHEL) and is identical in every way except for branding. There will be some discussion of the features found in Fedora and which may appear in future versions of RHEL and  CentOS.

See the Theory and Practice of Linux System Administration page for a complete course description and prerequisites.

Linux Servers and Advanced System Administration

This course is intended for experienced Linux System Administrators who wish to learn advanced troubleshooting techniques and server installation and configuration. 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.

See the Linux Servers and Advanced System Administration  page for a complete course description and prerequisites.

Discounts

Discounts are available to members of the Triangle Linux Users Group (TriLUG) of $500 per class. You must have and show your TriLUG membership card to obtain this discount. This discount may be used in conjunction with other discount offers.

Custom Class Scheduling

Millennium Technology Consulting LLC can provide customized scheduling for classes. If you do not see a class scheduled within your desired time frame we can work with you to schedule one that meets your needs. We also offer on-site training at your location. Please contact us to schedule a class for you.


01. January 2014 · Comments Off on Theory and Practice of Linux System Administration class, January 20 – 24 · Categories: Linux, News, Training · Tags: , , ,

Millennium Technology Consulting LLC, will be running the highly reviewed class, Theory and Practice of Linux System Administration, the week of January 20 – 24.

About this Course

This course is intended for  junior and mid-level Linux Systems Administrators who wish to advance their knowledge, and administrators of other Unix versions or Windows who wish to become Linux System Administrators. This class is heavily oriented towards hands-on activities. At least half of the class time is allotted to lab projects.  Experienced Linux System Administrators also find this class valuable. Taken from my own experiences accumulated during more than 15 years of using Linux, and developed using my knowledge and experience as a course developer and trainer for both IBM, Red Hat, and other companies, this class covers the practical aspects of Linux System Administration. It builds upon the foundation of the “Philosophy of Linux” in a way that helps the student understand how and why things are done as they are.

Our courses are always highly rated and well reviewed. Here are some comments from previous students taken directly from the course evaluation forms.

Course Description

The student will learn about the history of Linux and the philosophy of Linux and how it applies to the everyday tasks that she will be expected to perform. The student will install a current Centos Linux system on common Intel hardware, using various installation options to customize the final result. The students will learn to use the command line interface (CLI) and many basic Linux commands along with the vi editor. More advanced commands such as sed and awk will be covered and combining all of these commands into short command line programs will be discussed and the student will have opportunity to use them in lab projects.

This course covers the Linux boot sequence and the traditional SystemV init scripts as well as an introduction to the new systemd daemon for startup and daemon management. The student will learn to manage users and software packages. Networking, security, processes, filesystems and Logical Volume Management will be covered in detail.

For complete details of this course see the Theory and Practice of Linux System Administration page.


26. October 2013 · Comments Off on Theory and Practice of Linux System Administration class, November 11 – 15 · Categories: Information, Linux, Training

For the last time this year, Millennium Technology Consulting LLC, will be running the highly reviewed class, Theory and Practice of Linux System Administration, the week of November 11 – 15.

About this Course

This course is intended for  junior and mid-level Linux Systems Administrators who wish to advance their knowledge, and administrators of other Unix versions or Windows who wish to become Linux System Administrators. This class is heavily oriented towards hands-on activities. At least half of the class time is allotted to lab projects.  Experienced Linux System Administrators also find this class valuable.Taken from my own experiences accumulated during more than 15 years of using Linux, and developed using my knowledge and experience as a course developer and trainer for both IBM and Red Hat, this class covers the practical aspects of Linux System Administration. It builds upon the foundation of the “Philosophy of Linux” in a way that helps the student understand how and why things are done as they are.

Our courses are always highly rated and well reviewed. Here are some comments from previous students taken directly from the course evaluation forms.

Course Description

The student will learn about the history of Linux and the philosophy of Linux and how it applies to the everyday tasks that she will be expected to perform. The student will install a current Fedora Linux system on common Intel hardware, using various installation options to customize the final result. The students will learn to use the command line interface (CLI) and many basic Linux commands along with the vi editor. More advanced commands such as sed and awk will be covered and combining all of these commands into short command line programs will be discussed and the student will have opportunity to use them in lab projects.

This course covers the Linux boot sequence and the traditional SystemV init scripts as well as an introduction to the new systemd daemon for startup and daemon management. The student will learn to manage users and software packages. Networking, security, processes, filesystems and Logical Volume Management will be covered in detail.

For complete details of this course see the Theory and Practice of Linux System Administration page.


03. September 2013 · Comments Off on Theory and Practice of Linux System Administration class, September 23 – 27 · Categories: Announcements, Millennium Technology Consulting LLC, Training

My company, Millennium Technology Consulting LLC, will be running the highly reviewed class, Theory and Practice of Linux System Administration, the week of September 23 – 27.

About this Course

This course is intended for  junior and mid-level Linux Systems Administrators who wish to advance their knowledge, and administrators of other Unix versions or Windows who wish to become Linux System Administrators. This class is heavily oriented towards hands-on activities. At least half of the class time is allotted to lab projects.  Experienced Linux System Administrators also find this class valuable.Taken from my own experiences accumulated during more than 15 years of using Linux, and developed using my knowledge and experience as a course developer and trainer for both IBM and Red Hat, this class covers the practical aspects of Linux System Administration. It builds upon the foundation of the “Philosophy of Linux” in a way that helps the student understand how and why things are done as they are.

Our courses are always highly rated and well reviewed. Here are some comments from previous students taken directly from the course evaluation forms.

Choice of distribution

Students attending this class have a choice of which distribution on which they wish to concentrate and to use for lab projects. This class can be based either on Fedora because it is the upstream distribution for Red Hat Enterprise Linux (RHEL) and provides some insight into features and functions that may show up in RHEL in the future, or on CentOS as it reflects the current state of RHEL.

Course Description

The student will learn about the history of Linux and the philosophy of Linux and how it applies to the everyday tasks that she will be expected to perform. The student will install a current Fedora Linux system on common Intel hardware, using various installation options to customize the final result. The students will learn to use the command line interface (CLI) and many basic Linux commands along with the vi editor. More advanced commands such as sed and awk will be covered and combining all of these commands into short command line programs will be discussed and the student will have opportunity to use them in lab projects.

This course covers the Linux boot sequence and the traditional SystemV init scripts as well as an introduction to the new systemd daemon for startup and daemon management. The student will learn to manage users and software packages. Networking, security, processes, filesystems and Logical Volume Management will be covered in detail.

For complete details of this course see the Theory and Practice of Linux System Administration page.


02. September 2013 · Comments Off on Nine traits of the veteran Unix admin · Categories: Information, Linux, Unix

Here is a link to another article at InfoWorld that I really enjoyed. It is a couple years old but the content is timeless in the Unix and Linux worlds.

Nine traits of the veteran Unix admin


27. August 2013 · Comments Off on Stories from the dawn of Unix · Categories: History, Unix

Here is a link to an article in InfoWorld about the early days of Unix. These are reminiscences from some of the developers of Unix. I found it very interesting and perhaps you will, too.


26. August 2013 · Comments Off on Adding CentOS to Linux Training Courses · Categories: Millennium Technology Consulting LLC, News, Training

For the previous few years I have used Fedora exclusively as the basis for courses designed and taught as part of our Millennium Technology Consulting LLC training offerings. This is because Fedora is the upstream distribution for Red Hat Enterprise Linux and many features that eventually find their way into RHEL show up first in Fedora. Some features never make it into RHEL for various reasons—not the least of which being that they don’t work well or meet the needs of a commercial grade Linux.

On the other hand, CentOS is a downstream copy of RHEL, identical except for logos and branding. CentOS is for people who want to use RHEL but perhaps do not want to pay for services in order to obtain software updates. CentOS is always a few weeks or possibly even months behind RHEL because of the time required to replace all references to Red Hat with those for CentOS.

Extensive differences

The last few releases of Fedora have resulted in very significant differences between Fedora and RHEL, and therefore with CentOS as well. Current major differences include naming of network devices by UDEV and DBUS and how that works with NetworkManager, and systemd a completely new replacement for the SystemV start scripts that speeds startup significantly but requires a completely new set of commands.

Training issues

In the past, the differences between these distributions required only a bit of time during class to discuss. The current major differences require a different approach for training classes. They are just too great to cover easily in the amount of time available in these classes.

Due to it’s much closer match to RHEL these days, CentOS is much more attractive to administrators who need Linux training than Fedora.

New approach

I have devised a new approach to the structure of these classes and the course materials that will enable me to teach using the same materials for both Fedora and CentOS.

The new course materials for all courses developed by Millennium Technology Consulting LLC will cover both Fedora and CentOS. This means that presentation slides will cover those differences between distributions that are significant and meaningful. Lab projects will provide instructions for both distributions where differences exist in the commands or the tasks required to meet an objective.

The instructor will be able to teach using either CentOS or Fedora depending upon the needs of the students and the measure of the differences between the two distributions.

And after the class is over, the course materials can be used as a reference for both distributions.

So whether you need to prepare for what the future of Linux holds, or you need to know exactly how to do things with today’s distributions, Millennium Technology Consulting LLC can meet your training needs.

Check the Training Calendar for class schedules. We can also provide custom scheduling for classes that meet your own needs rather than mine.

Please contact us to sign up for classes as soon as possible. Our classroom facilities have very limited seating so class sizes are always very small.

 


10. August 2013 · Comments Off on Theory and Practice of Linux System Administration class, August 17 – 23 · Categories: Linux, News, Training · Tags: , , , ,

I will be running the highly reviewed class, Theory and Practice of Linux System Administration, the week of August 17 – 23.

About this Course

This course is intended for  junior and mid-level Linux Systems Administrators who wish to advance their knowledge, and administrators of other Unix versions or Windows who wish to become Linux System Administrators. This class is heavily oriented towards hands-on activities. At least half of the class time is allotted to lab projects.  Experienced Linux System Administrators also find this class valuable.

This class is based on Fedora because it is the upstream distribution for Red Hat Linux.

Taken from my own experiences accumulated during more than 15 years of using Linux, and developed using my knowledge and experience as a course developer and trainer for both IBM and Red Hat, this class covers the practical aspects of Linux System Administration. It builds upon the foundation of the “Philosophy of Linux” in a way that helps the student understand how and why things are done as they are.

Our courses are always highly rated and well reviewed. Here are some comments from previous students taken directly from the course evaluation forms.

Course Description

The student will learn about the history of Linux and the philosophy of Linux and how it applies to the everyday tasks that she will be expected to perform. The student will install a current Fedora Linux system on common Intel hardware, using various installation options to customize the final result. The students will learn to use the command line interface (CLI) and many basic Linux commands along with the vi editor. More advanced commands such as sed and awk will be covered and combining all of these commands into short command line programs will be discussed and the student will have opportunity to use them in lab projects.

This course covers the Linux boot sequence and the traditional SystemV init scripts as well as an introduction to the new systemd daemon for startup and daemon management. The student will learn to manage users and software packages. Networking, security, processes, filesystems and Logical Volume Management will be covered in detail.

For complete details of this course see the Theory and Practice of Linux System Administration page on our Millennium Technology Consulting LLC company web site.


10. August 2013 · Comments Off on Server migration complete · Categories: News

Our server migration was completed yesterday afternoon, Friday, August 9. All of our server functions are now back on the more powerful server hardware.

There were more issues than expected, but that is almost always the case with any upgrade or migration. As usual, some of the issues were self-inflicted. This included a problem with the method I used for migrating the web sites. But in the end, all of the problems were resolved in one way or another.

The Millennium Technology Consulting LLC web site is now running on CentOS 6.4. I chose this distribution because it has a long term support policy. Fedora, which I had been using for our server, has a very short support lifetime, so it is really a good deal of work to update the server every 12 to 18 months in order to stay current with security updates in particular.

CentOS has a 10 year support life so I do not expect to have to perform another migration or major upgrade on the server for a considerable time.

I still prefer Fedora for my desktops as it has more of the desktop features I like.

I apologize for any inconvenience that the outages during this migration may have caused.


04. August 2013 · Comments Off on Introduction to Linux class, August 8 and 9 · Categories: Announcements, Linux, Training

I am running an Introduction to Linux class this Thursday and Friday, August 8 and 9.

This two-day course is for anyone who is considering pursuit of a course in Linux system administration and who wants a brief introduction to Linux.

Course Outline

This course is a quick survey of various aspects of using Linux with both the desktop and the command line interface (CLI). It is intended to be 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.

The topics covered in this course include the following.

  • Exploring desktops
    • KDE
    • GNOME
    • Other desktops
  • Virtual Consoles
  • Screen
  • The Command Line Interface (CLI)
  • Processes
  • Managing Files
  • Vim Editor
  • More About Files
    • Permissions
    • Links

The course normally costs $1295 however there is a $500 discount for TriLUG members.

See http://www.millennium-technology.com/?page_id=1519 for full course details.


26. July 2013 · Comments Off on Server upgrade weekend of August 3-4 — short outages expected · Categories: Announcements, Site Outage

The weekend of August 3 and 4, I will be preparing to perform a significant server upgrade. The upgrade itself will take effect over a few days during the following week. You may experience intermittent short outages of this web site during this time, especially the weekend during the preparation phase.

I apologize in advance for any inconvenience these outages may cause.

The Plan

Just in case you are curious, here is the plan for this upgrade.

Preparation

Estimated outage: 60 Minutes

  1. Poweroff the original server and remove the hard drive.
  2. Install the hard drive in the temporary, less powerful server.
  3. Power on the temp server and properly configure the network adapters.
  4. Configure the firewall to forward email and web services to the temporary server.
  5. Test.

At this point we will be up and running with our same software but on a less capable host. The temporary server should have no difficulty dealing with the loads we normally experience, but I do want to end up with the more powerful computer as our server.

Implementation

Estimated outages: A few minutes at most during each transition.

  1. Install new hard drive in the original server.
  2. Install the latest version of Fedora.
  3. Install the server software required to run the email and web sites.
  4. Install all of my personal and server-related configuration customization.
  5. Migrate the web servers.
    1. Copy the configuration file for the Apache web server to the upgraded server.
    2. Copy the data for all web sites from the temporary server to the upgraded server.
    3. Verify that the web sites are working.
    4. Configure the firewall to forward web requests to the upgraded server.
    5. Test all of the web sites.
    6. Fix problems.
    7. Repeat E and F until all problems resolved.
    8. Turn off the web server on the temporary server.
  6. Migrate the email server.
    1. Copy all of the configuration files for sendmail, SpamAssassin to the upgraded server.
    2. Start Sendmail.
    3. Test.
    4. Configure the firewall to forward email requests to the upgraded server.
    5. Test.
    6. Fix problems.
    7. Repeat E and F until all problems are resolved.
  7. Migrate listserv.
    1. Copy list data and archives to the upgraded server.
    2. Verify correct operation.
    3. Fix problems.
    4. Repeat B and C until all problems are resolved.

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