I have been working on different types of applications on Linux, however I had a less chance to deep dive into linux kernel, the way it kernel deals with the HW, devices, memory handling, filesystems etc.
I want to be an L3/L4 linux engineer, and unfortunately I am not being given a chance to move to that kind of roles,
I am planning to move myself to that kind of role
where shud i start, what are next level commands or tools or utilities in linux ..

I understand this is not a career suggestion forums..however any L3/L4 members pls see if you can reach me

the next level commands? I assure you there is no secret command that you only get told about after some sort of initiation test. I would really suggest you stop thinking about "L4" people, whatever that means, and just apply for higher level jobs, and sell yourself. You need to make your own chances, not expect people to give them to you.

OK..

Would you explain what is L4?

Assuming this would be seen as "4th Line" then you wouldn't see "Linux engineers" in this role, you'd see Kernel developers, Enterprise architects, Freelance consultants and other things like that. Not Engineers.

Thanks, that was helpful. By "Linux engineers" you mean the system admins and application developers?

For kernel development issues, you need to understand:
0. The kernel compilation:
http://www.kernel.org/
http://tldp.org/HOWTO/IBM7248-HOWTO/kernel.html

1. The kernel modules:
http://tldp.org/LDP/lkmpg/2.6/html/
http://www.amazon.com/Linux-Kernel-D.../dp/0672327201
http://oreilly.com/catalog/9780596000028

2. The GCC compiler:
http://gcc.gnu.org/

3. The Make files:
http://www.gnu.org/software/make/
http://www.eng.hawaii.edu/Tutor/Make/

4. The kernel debugger:
http://www.linuxfordevices.com/c/a/L...-debugger-KDB/
http://www.ibm.com/developerworks/li...brary/l-kdbug/
http://www.gnu.org/software/hurd/gnu...-Debugger.html

and when you are ready:
http://www.kernel.org/pub/linux/docs/lkml/