May 3, 2012
March 18, 2012
Save power: sleep your Ubuntu home server
I don’t need my server on while I’m sleeping. Turns out Ubuntu servers love to sleep, too.
The first hurdle was nontechnical. I had to decide that I was ok not being on IRC while asleep. Once I made this decision, I realized it was the right decision anyway.
The next hurdle was scheduled late-night backups. They’re important. What if the server is powered down when a job is scheduled to run? Anacron to the rescue! When you install it on Ubuntu it transparently takes over daily, monthly, and weekly cron jobs. I installed anacron with
sudo apt-get install anacron
Now, to install a new daily backup job managed by anacron, the easiest thing to do is just add an executable script to /etc/cron.daily.
I also have a bunch of @daily stuff in my personal crontab. There are a couple more steps to get it working as a non-root user, but it’s doable.
To actually put the computer to sleep I use
sudo pm-suspendover an SSH connection (since the server is normally headless). The first time I tried this the box just froze, but I haven’t been able to repro that since I unplugged the VGA monitor and created swap space. Not sure which of those changes, if either, allowed suspend to work.
I’d also like to resume the box with wakeonlan, but it doesn’t work. Both machines are on the same switch, but the BIOS or ethernet card may not support wake-on-lan.
March 5, 2012
Squelch Doctrine/MongoDB logging in Symfony2
If you use Doctrine+MongoDB in Symfony2, you may have flood of mongodb queries in your dev environment log. Here’s a snippet of code for app/config/config.yml that will squelch them:
doctrine_mongodb:
document_managers:
default:
logging: false
February 28, 2012
SSH connections hanging: fixed by disabling TCP window scaling
This is mainly just for my own future reference, but you may end up here via a web search if you ran into the same problem.
I use Symfony2, which leverages Git to manage bundles (a.k.a. libraries). There’s a script called “vendors” which can (currently) be used to update bundles. Running bin/vendors install is a common operation: this descends into every bundle directory and pulls down the latest code. All of my own bundles are reached via git+ssh.
The git+ssh connections to update my bundles were hanging. There are many layers that could be malfunctioning, but I first suspected my failing Netgear wireless access point / router. Lately, weekly reboots have been necessary to even be able to associate with the thing. I also suspected my /etc/hosts.deny was too big, but these connections were really slow, hanging for minutes at a time (where they were usually instant).
I happened upon this old bug, and decided it might indeed be my router. I ultimately have no idea why, but here’s what fixed the hanging connections for me:
echo 0 | sudo tee /proc/sys/net/ipv4/tcp_window_scaling
I imagine this should be a temporary change, since it sounds like TCP window scaling generally results in more efficient data transfer.
I’m going to round file the netgear tonight, hopefully that’s the problem.
Other ideas:
February 5, 2012
Reading Webpages. Like, actually reading!
Forget surfing. Clicking from page to page, skimming paragraphs, forgetting it immediately. Someone spent quality time writing, I want to spend quality time reading. Like the good old days. Reading beautiful print on paper, understanding, thinking about what I’m reading.
Along these lines, I totally heart that “READER” trick iOS 5 Mobile Safari does with some webpages. Anyone know how to teach Chrome or Firefox to do the same?
If you haven’t heard of it, see http://www.apple.com/ios/features.html#gallery-safari-reader.
This is an absolute revolution in actually reading overstyled, ad-riddled online content. I even find myself hitting the READER button for fairly clean content because it always produces a consistent result.
This really shouldn’t be a revolution. We know people can read/concentrate/comprehend better without distraction!
Crosspost: https://plus.google.com/109728769351141658237/posts/TCsVTGf5jeM
Update: Krzysiek Głębowicz mentioned Readability and I found dotEPUB.
January 31, 2012
Auto-update bind 9 zone database serial numbers
This post is helpful for configuring emacs to automatically update the “Serial” in bind zone databases. I wanted to do the same in Vim, but the solutions in the comments of that post didn’t work for me. Here’s a version that does. It’s yours for free under the Affero GPL v3 (or any later version, at your preference):
function s:BindZoneSettings() function s:UpdateBindZoneSerial(date, num) if (strftime("%Y%m%d") == a:date) return a:date . a:num+1 endif return strftime("%Y%m%d") . '01' endfunction function s:ReplaceBindZoneSerialLine() :%s/\(2[0-9]\{7}\)\([0-9]\{2}\)\(\s*;\s*Serial\)/\=UpdateBindZoneSerial(submatch(1), submatch(2)) . submatch(3)/g endfunction autocmd BufWritePre /etc/bind/db.* call ReplaceBindZoneSerialLine() endfunction
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January 5, 2012
December 31, 2011
Browser Pause
Here’s an idea for Web browsers. When the browser window loses focus, stop everything. Freeze all threads, animated images, scripts, plugins… everything. This would be most useful as a setting that could be enabled and disabled at will. Sometimes I’d just like the browser to just simmer down while my attention is elsewhere. No need to be AJAXing around and stuff.
Thoughts?
December 22, 2011
Don’t Get Locked In
Here’s a Public Service Announcement for those of you who wish to buy an iPhone and might want to use it for a different carrier than the one the phone is locked with.
You can’t.*
If you buy an At&t iPhone, Apple says Thou Shalt Only Use Thy iPhone with At&t, and makes it very difficult to use the phone with, say, T-Mobile. You’ll get to use the phone, but At&t and Apple really still own part of it, the part that says how the phone can be used.
Strange, isn’t it? It’s like you bought a roll of duct tape, but it only works on ducts.
Other ideas:
- buy an unlocked iPhone instead. iPhones hold their value well, especially unlocked ones. They cost a lot more so the upfront cash required is high, but an unlocked phone gives you the freedom to change carriers anytime for any reason. When you figure out the price of the phone, don’t just look at the initial price, look at the cost of the contract over the life of the contract and check prices on similar used unlocked phones on eBay.
- don’t buy an iPhone. By purchasing an iPhone you’re telling Apple that you’re willing to pay the price of your freedom. Apple pushes hard on its customers, saying what they can and can’t do. They sure do make awesome technology, but at the cost of personal freedom.
Learn more about freedom at https://www.eff.org.
* If you are brave, patient, lucky, and desperate, you may be able to bypass the electronic measures in place which lock the phone to At&t.
October 8, 2011
Does the FSF need better top-down social skills?
Larry Cafiero and Joe Brockmeier are two big voices for technological freedom. They’re both pretty fired up about RMS’s f-you epitaph of Jobs.
Generally you want the figurehead of a public foundation to be, uh, attractive. Intellectually, maybe even physically. Right? Not only does the cause itself have to make sense, these people need to attract other people to their cause. And they usually “say the right things”, smile, wear a suit, whatever. But I always thought these requirements only applied to other causes (besides Free Software).
Certainly RMS lacking those traits didn’t keep me from FLOSS. I heard about RMS and the proprietary printer a while back, and that’s all it took to get me hooked on FLOSS. I could identify immediately because I write software, and proprietary code is a pain. His cause just makes sense, even if he doesn’t. But I’ve been justifying his abnormal behavior because, well, he started something new! Something important. He knew it was important, and dedicated his life to this thing that many, many folks never even know exists. Something that affects all our lives, every day, more and more. Software must support our Freedom, or we are not free.
So he won me over, but I’m a nerd. I’m used to eccentrics in my field. Truth wins, period. And I still don’t know if it matters if RMS is a polished, smiley, public-friendly dude or not. Would Free Software be farther along today if RMS were kinder, more respectful, or somehow a better “public figure”? Would DRM have never been allowed to exist? Would the government pass laws that software for implanted medical devices be Free?
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