There is just one phone interview..and it is entirely technical..Though the title says Linux admin..you need to know more than that..like serialization(JAVA),OOP,arrays and if you know databases..then great..The linux questions are pretty straigtforward..know the basic commands like cat,grep,ls,tar and so on..
Weird thing is I was initially rejected by a staff..and then his supervisor interviewed me again after a month and I was offered the job