The first interview I had was on the phone, with the recruiter. She asked me basic questions about previous work history, current work experience - Nothing too difficult or technical here. She then bounced me around to another recruiter, who later set me up with another phone interview.
The second phone interview was with a manager from Austin Rackspace. So there was some technical discussion involved - basic Linux / bash, iptables, resource usage troubleshooting, how to find information about the system and so forth. This is not very difficult if you have relevant experience.
The manager, after determining that you are technically proficient enough, will set you up (through the recruiter) for a TrueAbility test. TrueAbility allows you to log onto a server set up exclusively for Rackspace technical questions (traditionally called a "break box" fix or test).
The server was Centos and the questions were mostly about Apache2, Postfix, PHP, and mySQL. Please be expected to identify / edit / fix each service's configuration files. You will also need to utilize basic bash / mysql cli skills in this test (for example, how to place all incoming TCP connections into a file; or, how to import/export databases from mysql cli).
I had one hour to work on this. As you are by yourself, you can Google as needed.
Each follow-up from Rackspace took about a week or a week and a half through the recruiter via email.
My new recruiter let me know that they'd like to see me in person. So, I was set up with my 4th interview in person, in the Austin office. Prior to this, you have to set up a "racker talent" online profile where you essentially fill in another official application.
This interview was by far the most difficult. It was three hours long, and consisted of two 1.5 hour interviews with three people each. The first section of people were all admins, higher tier. They had me sit on a company laptop which was hooked up to a TV in an interviewing office. From there, they had me enter screen and asked me some Linux quiz-like questions; their expectation is to have you display as much as skill as possible. Be prepared for scrutiny. They will ask you additional technical questions, i.e. to elaborate on a particular command, or to explain what something would be used for in a real-life situation.
If you are not familiar with x, but you bring up x anyways, they may prod you to make sure you REALLY understand what it is you're talking about. To some degree, I suspect they are trying to understand technical limits. Do your homework! And if you're really not sure, say so; we are all human, after all. I learned a few things after walking away from this interview for sure.
The second half of the interview was their HR team; they asked about customer relationships, and how you handle yourself in certain environments, as well as what steps you'd take in particular situations. Example: What would you do if you accidentally deleted a customer's database, even if you could restore it in 30 seconds? Or: If you had to reboot a customer's server to resolve an issue, how would you handle that?
I didn't get an offer after this interview - I got a voicemail stating they'd made a decision, and that other candidates were chosen. This was understandable because of some lack of technical knowledge.
Three months later, a recruiter contacted me, inquiring about another phone interview. They wanted to give me a 2nd chance since I'd made a good impression the first time around. The phone interview was nothing special, just re-hashing everything I'd gone through and discussed so far with the team. On the same call, the recruiter set up another in-person interview in the Austin office.
The interview was still three hours. However, this time I had three one-hour sessions with two people each hour. Instead of having technical and relationship questions separated, all three sessions combined the subjects. For some questions there was a whiteboard - "Draw me an example of a basic Apache VirtualHost." "If you had all the money in the world, what kind of servers would you set up and why?"
Other questions that I remember:
"If a customer stated their website was slow, what exact steps would you do to troubleshoot it?"
"If a website was reported as completely 'down', what would you do?"
There are many "stream of consciousness" technical questions like these - they can be very open to interpretation. Don't feel obliged to reply perfectly, just tell them what you'd do, and how you'd do it.
Of course, there are also questions such as, "Are you familiar with our products, and can you explain them to us?" "What do you know about load balancing?" "Have you worked with mySQL replication?"
About a week and a half later, the recruiter called me back with an offer which I accepted.