I spent a few hours on the wrong side of that riddle recently.  

Most of the engineers here at OpenLogic work in some flavor of Linux on their development machines.  When I first received my laptop I attempted to join the crowd and install Ubuntu.  However, due to hardware issues with the video and wireless chipsets on the machine I got, I reluctantly decided to back out and go with the standard issue Windows XP and am still running that today.

This past week I joined a new project team working in Ruby on Rails.  Having been previously focused on Java projects, I had to install and configure a number of things to get up and running in the new development environment.  Part of that setup involved installing a MySQL instance used by the application.  

Once I had everything ready to roll, I wanted to run "rake test" to verify that all the tests passed.  Well, they didn't.  I realized that I initially set some things in the MySQL configuration to be too restrictive.  I'll spare you the details, as that's not the point of this blog post.  So, I reconfigured, based on the settings another developer had working in Windows.

I ran "rake test" again.  Things were looking better.  Tests were passing.  Feeling good.  Nope, boom, suddenly failures left and right.  I ran "rake test" again and got failures from the start.  The errors that were occurring repeatedly looked something like this:

ActiveRecord::StatementInvalid: Mysql::Error: 

Can't create/write to file '#sql_1830_0.MYD' (Errcode: 17): SHOW FIELDS FROM tags

The file it was trying to write to was in the temp data directory under the MySQL installation.  I messed with file permissions.  I deleted the temp file and ran again.  Things started off well, but started failing again mid-stream.  I was trying my best to apply logic to the situation rather than jump to the typical re-install, reboot approach it's so tempting to take when things go wrong in a Windows environment.  I decided to peruse some Google search results a little deeper than I had at first.  Thankfully, I followed a link to a post on an Alfresco forum.  Obviously the issue I was dealing with had nothing to do with Alfresco, but was dealing with the same MySQL error.

There it was: "The problem is fixed now. Newer version of McAfee was protecting MySql temporary folder."

No way.  Could that really be it?  I am running McAfee…  I temporarily disabled the virus checker and ran "rake test" again…  Success.  All the tests passed.

Unbelievable.  I honestly don't know that I would have ever thought of that as the possible cause of the problem.  Let me just say I am thankful when people like Senthil follow up their posts with the solution they found, even when it wasn't one someone suggested in a reply.  Then again, if I hadn't found the solution, maybe this would have been the impetus to finally get Linux working on my laptop.  Then, afterall, I wouldn't have much need for a virus scanner anymore.