When I first started my IT career years ago I would generally come across two different types of system administrators. Those who used Windows and those you used Linux, I rarely found someone who used both frequently. I spent my first four years in an all Windows environment, learning technologies such as Active Directory, Exchange among others. Sure I knew what Linux was, but I had no desire to take on learning another entirely different operating system from what I already knew not to mention there was no business need at that time.
As I changed jobs in started working in different environments I began to be introduced to Linux because that was used for web servers, LDAP, SMTP and such in these organizations. At first, it was daunting because once you know one OS, trying to learn something that looks and feels much different can be quite difficult. Having a knowledgeable Windows administrator who is used to a GUI login into a completely CLI based server for the first time will send them to a psychiatrist quickly. To be fair, expecting a Linux admin to login to a Windows server and accomplish a complex task will make them look downright stupid if they don’t have experience doing it. Thus, this is an example of the toughest obstacle of learning a different OS when you know the other one so well. Yourself.
I recently had an intern ask me about what I thought he should learn if he wanted to become a system administrator. This is actually a pretty easy question because if you search for jobs in areas such as New York, you will find what employers are looking for in terms of skills. So I wrote him a list:
OS – Windows, Linux (CentOS, RedHat)
Web servers – IIS, Apache
Programming – Bash, Python, Powershell
Cloud – AWS, Azure
Networking – Study CCNA material
There is a lot you can add to this list, but I think it is a good start for a novice who is starting out. The important part of this list is that it is cross-platform so that it forces the student to not get too comfortable with one that they don’t want to learn the other. Not focusing solely on one OS, but both. Employers want to hire IT professionals that can operate on Windows and Linux, but why? To an employer, a system is a system. If they are using both operating systems (and most of them are) then you are no use to them if you only know one.
So this latest generation of sysadmins will prove to be the last who only know one OS, at least if they want to stay a viable candidate for jobs. There will always be preference in an OS by a Sysadmin, but the luxury of only knowing one or the other will soon be over.