NrvrCommander automation release


What may matter most about the free and open source NrvrCommander: It is in actual use.

What it is

NrvrCommander makes virtual machines, and it controls them for automation.

NrvrCommander does at least some things other automation software doesn’t, or didn’t when we looked.

For example, in NrvrCommander’s example scripts the starting points are original OS distributions, from there on scripting, not requiring acceptance of pre-made VM snapshots. Your appreciation may depend on whom you trust and how many variations you need. In addition to transparency (review, audit) and flexibility (variations by coding a few lines), scripts take arguably 10-5 of the storage space of snapshots. This is not mandatory, not a limitation: You could start from snapshots, and one example script cleverly uses snapshots.

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Adj features galore


This is an announcement of new features of the open source Adj framework, which is at version 3.5.6.

The original announcement of Adj still has relevant information which is not being repeated here. So does the version 2 announcement.

For a formal reference, there is the user guide.

What is new:

Aquifer Depletion in California’s Central Valley and Santa Clara Valley


This is a summary of sources.

More than a century of data in USGS Circular 1182 Land Subsidence in the United States , specifically:

Those three files contain different information each. They are worth looking at each, all pages, even if you don’t read all details.

About 2013 activity in Stanislaus County, notable articles for numbers mentioned:

Hoping this compilation will help in coming to good decisions. It has been written preemptively, to supply science and history when discussions, as regrettably too common in contemporary politics, would become too sidetracked or partisan.

Additional info re Santa Clara Valley at .

NrvrCommander documentation DIY


NrvrCommander should have more documentation. Today I write why I don’t write more documentation today.

There is some good documentation already.

If we would wait for perfection, we would be withholding a working tool.

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GUI on headless Linux server [SOLVED]


I merely wanted to run NrvrCommander to do load testing with Selenium – a combo working quite well – but circumstances forced me to first regain control of a remote computer I had been driving just fine until one morning VNC stopped working. Presented is a documentation of working solutions, and how we got here.

The failure of VNC started with no clearly identifiable single cause. There have been multiple causes:

• Possibly one trigger of events has been a network reconfiguration at the site hosting that remote computer. Cannot be certain.

• Another trigger may have been a reboot behind that site’s KVM switch switched to a different computer and our computer not receiving EDID information – apparently a weakness of that specific KVM switch.

• Another problem has been a known issue with the operating system’s built-in vino-server storing the password differently in some versions under some circumstances, which wasn’t obvious at all, specifically if not seeing the remote screen.

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Cooling a notebook computer on a deadline


Thursday 10pm knew this notebook computer fan is dying, way noisy. By 11pm knew a warranty replacement would be here Monday at best [got here Wednesday]. Working on a different computer would have been daunting. How to keep this one working?

Tried to install software to control fan speed, maybe avoid resonance frequencies. No luck despite several related utilities such as GNOME Sensors Applet, fancontrol, and dellfand (found via I8kfanGUI). Reading the fan speed was possible, controlling it wasn’t. Went to sleep.

Friday morning decided to blow air through the computer with a fan we had made for breathing clean air when soldering: An old computer fan on a cell phone charger. Apparently a blade had broken, so it was rattling too much. Time to make another one like it.

Found fan on motherboard on kid’s bookshelf. Ran it from adjustable power supply to find right voltage for reasonable fan speed. For a 12V DC labeled fan that was about 7V. Found a leftover power supply 6V DC. Verified with multimeter it did output a voltage matching its label, verified with adjustable power supply 6V would spin fast enough. Cut wires, soldered wires, hot glued and electrical taped it up. Grabbed leftover lumber and kids’ building blocks and stuck it under the notebook, aligned to blow where the built-in fan should blow.

notebook external fan

Making a Notebook External Fan

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Internal-gear hubs on bicycles


Before there were derailleurs there were internal-gear hubs. I was brought up appreciating the low maintenance needs of Sturmey-Archer 3 speed hubs. Around 1999 I couldn’t get one where I lived, ended up riding a Shimano Nexus Inter 7-speed. That 7 speed is dead now in 2013, a can of metal shavings, possibly worsened by unwisely riding it under water this winter. This creek hasn’t stopped me yet, but after hydrolocking a truck engine around 2003 it contributed to an early demise of my hub this time around – same creek, different crossing. For me to learn limits.

Now I’m working on replacing the hub with a NuVinci brand continuously variable transmission. Fascinating different mechanical design. I did not see it coming. Reviews by owners seem to be positive. Putting it into my existing bike. We’ll see how that performs, ask a few months from now.

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50 years of constraints in computer graphics


In the early 1990s I gave presentations on using graphics in software development, several times with Alan Kay in the audience. At one point, I believe to remember, he mentioned he hadn’t seen that kind of vision or clarity since Sutherland‘s Sketchpad. Two decades later I downloaded Sutherland’s 1963 thesis, and read some of it.

Recently I searched Sutherland’s Sketchpad thesis for the word “constraint” and found it 127 times in 143 pages.

To quote verbatim from Chapter I, Introduction:

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