If you're running a complex web site, switching data centers can be a tricky business. That's true whether you're moving across the street or across town, and it's particularly true if you're lugging equipment across the country. Last month the Bloglines feed-reading service relocated from an AT&T data center in Redwood City, Calif. to an MCI facility in Bedford, Massachusetts used by the service's new owner, Ask Jeeves. The entire move is chronicled by Bloglines founder Mark Fletcher in a series of five posts on his blog. "This was a challenging and complex undertaking that required months of preparation by many groups," notes Fletcher, who suffered a broken toe during the move. "All growing database-driven Internet services have scaling issues. That's just a fact of life. So, in the midst of all this, we couldn't stop working on improving the existing Bloglines site. It made for an interesting juggling effort." If you've ever switched data centers, or if you're thinking about doing it any time in the future, you'll want to read Fletcher's account.