UPS power consumption

Recently I migrated my home server (a Linksys NSLU2 a.k.a. ‘Slug’) to a more powerful device (Mac Mini). The Mini has more capabilities and hence will run more services. Time to invest in a UPS that will keep the computer running when the electricity grid goes down.

Since the power consumption of my home server is a major concern to me, I’m also interested in the extra power consumption generated by the UPS.

I was able to measure the power consumption of a MGE Ellipse 750. Power was measured with a Voltcraft Energy Check 3000 and the test load was a normal PC (note: not the Mac Mini!).

The result was: the setup consumes 76 Watt without UPS and 80.5 Watt with the UPS. Note that the batteries of the UPS were fully loaded when the measurement was done.

Setting the execute bit in SVN

When committing files to an SVN repository, it happens that I forget to set the proper ‘execute’ permission.

This results in problems when checking out a fresh working copy, as it seems that SVN does not take up a ‘chmod u+x’ on a file as a change when a commit is performed.

This is easily fixed: just do

$ svn propset svn:executable ON somescript

And then commit.

Unroute a complete PCB in Eagle

Unrouting a complete PCB in Eagle means that all routed tracks on the board are reverted back into so-called ‘airwires’. Airwires are lines that show that there is a connection between 2 points on the board, but that no actual connection is routed yet.

Unrouting signals on a board is called ‘ripup’ in Eagle slang.

Continue reading Unroute a complete PCB in Eagle

Automatically mounting USB drives on Mac OS X

When plugging in an external USB drive on Mac OS X, it gets nicely mounted under /Volumes and appears on your desktop.

However, since I use my MAC mini as Slimserver machine for my squeezebox, I want this automount also to happen after boot, before a user is logged in.

This seems not to be so trivial. I’ve tried several mechanisms to obtain the automount feature, from scripts executed at boot time to modifiying the fstab. None provided an acceptable solution.

Continue reading Automatically mounting USB drives on Mac OS X