Using Scalpel to Recover Lost Data in Ubuntu

So there I was, editing my personal writing journal. I realized that the file had somehow lost a large chunk of data, and only had the last few entries. My backups had the same information, so I was staring at six months of data loss on an important personal file.

This post covers how I got the data back, good as new.

Is the disk bad?

The first thing I did was to search through the hard drive to see if the text was lying around somewhere in another file or I had deleted a vim swap file. When you use vim (in my case, gvim), by default it creates a file when you are editing it. Then, if the machine goes down while you are editing it, you can restore the file from the autosaved swap file. Unfortunately, I didn't find the data on my hard drive after searching around.

The disk itself didn't seem to be having any problems. There were no audio indications of failure, and no other files missing to the best of my knowledge. However, I figured that I should run a disk check to ensure that I wasn't dealing with the early stages of more widespread data loss. Tools like fsck require that you run them when the drive is not mounted, so I needed to find a way to unmount the drive and run it. Since I was running Ubuntu, I found a helpful command:

` sudo touch /forcefsck `

This tells Ubuntu to run fsck on the next startup, before the file system is mounted. I ran this, and the file system appeared to be the same.

So how did I lose data?

The file is my 2011 journal, and I really wanted to get it back. My best guess as to how this happened was:

Read on →

smtp.rb:14: [BUG] Segmentation fault

I just fixed a problem that I was running into on my Mac development machine. Things were running fine in my production environment (Heroku) but when I tried to send mail locally, I got the following error:

> rails c        
Loading development environment (Rails 3.0.8)
ree-1.8.7-head :001 > MyMailer.daily_email.deliver
~/.rvm/gems/ree-1.8.7-head@mygemset/gems/mail-2.2.19/
  lib/mail/core_extensions/smtp.rb:14: [BUG] Segmentation fault
ruby 1.8.7 (2011-02-18 patchlevel 334) [i686-darwin10.7.0]
zsh: abort      rails c

Hmm. I indeed use SMTP to send mail, but nothing too crazy. Plus it worked in production, and up until recently it was working locally. For more background, I was also using the Sendgrid plugin.

Read on →

The State of Ruby and Testing

At the May 2011 Indy.rb meetup, I suggested creating a survey to figure out what versions of Ruby people were using, and what testing stacks they use and would like to use. I created this survey and tweeted it out, and was impressed with the results! Over a hundred people filled out the information, from several continents and numerous countries. Thanks to everyone who participated!

The questions and their results

  • What versions of Ruby have you ever tried out?
  • What versions of Ruby do you currently use in production or for real apps?
  • What testing frameworks are your active projects using?
  • If you were starting a new Rails project right now, what testing frameworks would you use?
  • What mocking/stubbing frameworks are your active projects using?
  • If you were starting a new Rails project right now, what mocking/stubbing frameworks would you use?
  • What do your active projects use to populate testing data?
  • If you were starting a new Rails project right now, what would you use for populating testing data?

What versions of Ruby have you ever tried out?

Summary: a wide variety of Ruby versions used. What the heck is kiji, you might ask? This was a useful post on kiji.

What versions of Ruby do you currently use in production or for real apps?

Read on →

Ruby Filter Script

It's pretty easy to use a ruby script as part of a Linux or Unix pipe process to filter output of another script or set of commands. You can just use something like the following:

#!/usr/bin/env ruby

while line = STDIN.gets
  puts "filtered: #{line}"
end

The STDIN.gets is the magic. It just takes whatever the output of the preceding scripts and pipes it in. Then you can make the script executable and run it. If this script is named filter.rb, then you could run something like:

Read on →