How long does it take to become a Linux or Unix Administrator?

Was wondering how long does it take to become an entry level Linux or Unix administrator? I mean what is the minimum time required to be able to seek for a job at an entry level.





Thanks for your time.

How long does it take to become a Linux or Unix Administrator?
Normally employers require minimum of 3-5 years, but recently I saw one employer require one year experiences. Most small size company or a department of a big company need one Linux/Unix administrator, but if you find a company requires more than one person, then you have a change to work as assistant and also and a admin. People step up that way because there is not any company hires an entry level with no experiences to control the whole system (even the system has only 1-2 unix servers).