Remote Display Protocols in Abundance

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Over the years I've used a number remote display products.

VNC

The first one I recall using was Virtual Network Computing aka VNC in 1998. VNC is free software and has been incorporated, forked and enhanced by a number of companies and projects. While VNC works rather well over a medium to high speed LAN, it can be a bit slow over slower connections. That is because VNC isn't a completely vector-based protocol and still uses mostly bitmaps... or at least that is my understanding. One good thing about VNC though is that both the client and the server are available for Windows, Mac, and Linux... and a few other things as well.

Let's examine a few alternatives.


Tales of Enterprise Linux Major Version Upgrading

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In the last post I mentioned that I migrated from CentOS 4.9 to Scientific 6.1... and that certain aspects of this Drupal 4.7.x site were broken because of an incompatibility with PHP 5.3.x.

Downgrading a distro

Well, I decided to move from Scientific Linux 6.1 to Scientific Linux 5.7. EL5 offers both PHP 5.1.x and PHP 5.3.x and Red Hat announced a few weeks ago that they are extending the support lifecycle of both RHEL5 and RHEL6 from 7 years to 10 years. Migrating back to EL5 fixes the issues (knock on wood) that I was having with Drupal... but yet I can easily move to PHP 5.3.x at some point in the future if I so desire.

Doing EL major version upgrades

Two friends of mine happened to have CentOS 4.9 OpenVZ containers as well. They also run a number of services I'm less familiar with and weren't really versed enough with Linux to migrate their data like I did. In an effort to help them out, I looked into how to upgrade from EL4 to EL5. That really IS NOT supported or recommended but I thought I'd give it a try and see how it went. If it failed, I'd roll back to the original system. If it succeeded I'd keep it. After much work I *THINK* I figured it out. At least it worked for me in the particular situation I was dealing with. I started off with a page on the CentOS wiki about Upgrading from 4.4 to 5. I did not do a boot media based upgrade (I'm working with containers) so I did it strictly with rpm and yum.

I followed the instructions but they were written some time ago and were a bit outdated. So the first container I did took the longest because I was finding my way. Basically this happens in a few steps.

  1. Install the EL5 repos
  2. Manually download the core packages recommended and install them.
  3. Hopefully when you are done rpm is still working. If yum is broken, manually install a few more packages to make it work.
  4. With a working yum, upgrade everything else
  5. Turn off any new services that happen to be on by default that you don't want
  6. Find any stray packages left over from the previous release
  7. Fix your service configs by comparing your original service configs with the new ones

Read on to find out more of the nitty gritty details.


Site Upgrade - About time

Rackable NM46X Dual Quadcore AMDRackable NM46X Dual Quadcore AMDWarren Sanders put together a newer server to host this domain on. The system we were using was put together about 5 years ago. When we originally set it up, it was running CentOS 4.0. It was upgraded with each CentOS update and worked its way all the way up to CentOS 4.9. Anyone using RHEL 4.x or a clone can tell you that it is rather old in the tooth. For example it uses PHP 4.x.

A few weeks ago, I migrated all of our OpenVZ containers to the new system. The host node is running Scientific Linux 6.x. The containers continued to run CentOS 4.x Today I decided to make a new container and migrate all of the accounts and data to the new system. I basically went from CentOS 4.9 i386 to Scientific Linux 6.1 x86_64. The migration went pretty smoothly. My wife has a couple of Drupal 6-based sites and they just worked. I have a few Drupal 4.7.x based sites (which includes this one) and there were some issues. The main problem is that the Drupal 4 series is no longer supported / updated... and there are a number of known issues with Drupal 4.7.x and PHP 5.3. Going from PHP 4.x to 5.3.x is indeed a big jump. I also tried using the binary files for MySQL but ran into problems and ended up using mysqldump to export everything to an .sql file and then importing it. I don't know if the issues I ran into were caused by the big jump in MySQL versions or simply because I switched from 32-bit to 64-bit.

Any any event, with my testing and a little bit of php source code editing, this site is back in operation. It took me a couple of hours and there are still a few issues. What issues are those? Well, there will be no new account registrations and existing users can't edit their account information. Other than that, everything seems to work well enough.

I eventually plan on creating a new, Drupal 7-based site. I think trying to upgrade from the existing version through 5, then 6 and finally to 7... would be very problematic... unless there is someone out there who has done it. Problems with upgrading are what have held this site back at Drupal 4. Also being on CentOS 4.9, it was impossible to use Drupal 7 because it requires PHP 5.3.x at a minimum. I'm not really sure how I'm going to go about it... run both the old site and the new site... and manually copy and paste content between them? Or maybe I'll just run the old site in read-only type mode... and just use the new site for new content only. We'll see how it goes. I don't currently have a timeframe for when I'll set up the new site... so my guess is that this site will limp along for a while yet. Just wanted to let everyone know about the big change made today.

Screencast: Virtualization Basic Introduction

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I was asked to put together a presentation on Virtualization... and wasn't quite sure what the audience would want... so I put together a basic introduction that I can easily improvise on as the audience asks questions.

I designed the slides using Prezi which is a freemium web-based presentation site. It has lots of motion so watch out... but I did keep it rather simple - no pictures nor embedded videos. :)

virtualization-prezi.webm (12.7 MB)

Videos: Linux.conf.au 2012

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Bruce Perens was one of the keynote speakers at the 2012 Linux.conf.au conference held in Ballarat, Australia January 16-20, 2012. I really enjoyed his presentation so I'm sharing it below. The linux.conf.au folks have posted videos for all of their presentations to their YouTube channel. I downloaded all of them and posted them to an archive.org LCA2012 page. They are also available in ogg format.

LCA2012-Keynote-Bruce_Perens.webm (168.1 MB)

Video: OLPC Tablet reports from CES

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OLPC News: The OLPC Tablet at CES?

OLPC Tablet A1 board prototypeOLPC Tablet A1 board prototype

It seems that the upcoming OLPC XO 3 Tablet is getting some buzz right before its debut next week at CES. It is said to be an 8" tablet that may come in a few models. Information about it is currently very sketchy but supposedly some will be revealed next week. I am NOT posting any of the early concept pictures because they are dated and I'm fairly sure the real thing looks quite different... since it is designed to be very rugged for children. Here are some external links to get you in the mood:

COMPUTERWORLD - OLPC's XO-3 tablet to debut at CES

ELECTRONISTA - OLPC XO 3.0 tablet to show at CES with Android, Sugar

ENGADGET - OLPC outs XO 3.0 tablet at last, will make its debut at CES

GIZMODO - The $100 OLPC Tablet Is Really Real and Debuting at CES

OLPC News - What Will OLPC Show at CES 2012 Next Week?

OFFICIAL OLPC WIKI - XO-3 Tablet Alpha test model

There is a lot of repeating of the same speculation (echo chamber) and even some misinformation... but at least there appears to be some interest. For one thing the XO 1.75 is NOT out yet (March 2012?). They are keeping the Pixel Qi screen layer that gives it an eInk display mode just like in all previous OLPCs... but probably not in the $100 model. I think both Amazon and Barnes & Noble really missed the boat when they DID NOT but the Pixel Qi eInk layer in the displays of their Kindle Fire and Nook Tablet products. An eInk display mode in a color display from book sellers would have been a no-brainer. Who would of thought the OLPC project would have remained innovative with a 5 year old feature they pioneered?

I have to wonder if the OLPC folks have finalized the design and all of the models they plan to offer and what features they will have. I doubt it because the alpha board appears to have arrived about a month ago and they said they have more shrinking to do and a few more features to add... although it is currently half the size of the XO 1.75 board. The $100 model will almost certainly sacrifice some features because they can not sell them at a loss and make up the difference with "content sales" like the commercial vendors.

Is the $100 entry-level price hard to believe? Not really. The upcoming $25 / $35 Raspberry Pi devices (not shipping yet but probably within a month) have shown that modern SoC designs can actually be inexpensive. The OLPC XO-3 Tablet will have more hardware features than the Raspbery Pi including the not-cheap display, camera, wifi and battery (although no wired network port).

While the low price points are definitely achievements, there are three factors that make such pricing possible:

  1. Both OLPC and Raspberry Pi are non-profits
  2. Both are using completely free (speech and beer) software
  3. Both are aimed at the education market

One big difference though is that the OLPC project remains focused on only selling in bulk directly to governments and school systems whereas the Raspberry Pi is targeting single-unit direct-sales to the public.

Update: I found some images of the real external design. It is supposedly going to be shown early (Sunday night). The images look real and to the best of my knowledge, they are... and some ports are visible. Note that the thickness is what you'd expect in a rugged device... and is very reminiscent of the display-half of the current OLPC models. Since the existing OLPC models ALREADY had all of the guts behind the display (with the exception of the battery), this is definitely what I was expecting... but the lids are a surprising twist, eh?

OLPC XO 3.0 Tablet with coverOLPC XO 3.0 Tablet with cover

Two OLPC tablets, one with solar panel charging lid(?) and other with flexibleTwo OLPC tablets, one with solar panel charging lid(?) and other with flexible

By the way, a package showed up in my mailbox yesterday... a long lost OLPC XO 1.5. I just updated it to the latest stable software release and will be revisiting it since I haven't gotten much time with a 1.5. It will be available in the OPLC Lending Library RSN.

Video: Opencast Matterhorn

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At Montana State University - Bozeman, they use Camtasia Relay for lecture capture and distribution. I wasn't even aware that there was an open source alternative until I saw an "Ask Slashdot" type article where someone asked about lecture capture software... but yes indeed there is the Opencast Community / Projects and the system they have produced, Matterhorn. Check out the embedded video below which is an introduction. As far as I can tell, it (only) offers Flash-based video but I'm relatively new to it and haven't gotten all the details yet. So far as its capabilities and features go, it seems quite impressive.

Screencast: Pear OS Linux 3.0 "Panther" for Mac OS X fans

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I threw together a quick screencast that shows the recently released Pear OS Linux 3.0 "Panther" in action. Pear OS Linux is stylistically patterned after (some would say ripped off from) Mac OS X. It is my understanding that this is based on a customized GNOME 3.2 that shows yet again, just how malleable GNOME 3 can be with some effort.

Please excuse the SPICE connection glitches witnessed in the video. I generally don't run into issues with SPICE but this setup was a bit different with the visual affects that are turned on by default in Pear OS.

pear-os-linux-3.0-demo.webm (22.3 MB)

Screencast: History and differences of Xen and KVM

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I threw together a quick screencast for Dann from the Linux Link Tech Show explaining the history of and differences between Xen and KVM. Feedback is encouraged because I'm sure I have some mistakes in there.

xen-and-kvm-history.webm (36.2 MB)