Complete Lamp and Linux course training .pdf
Original filename: Complete Lamp and Linux course training.pdf
This PDF 1.5 document has been generated by Microsoft® Office Word 2007, and has been sent on pdf-archive.com on 19/09/2016 at 07:53, from IP address 122.166.x.x.
The current document download page has been viewed 342 times.
File size: 81 KB (2 pages).
Privacy: public file
Download original PDF file
Complete Lamp and Linux course training
Linux Kernel today is one of the large scale open source project which includes a 13 million plus
number of codes.
Definition of Kernel:
A Kernel the lowest level of software that is easily replaceable and that interfaces with the system
hardware of the computer. It works on interfacing down all those applications which are currently
running in the “user mode” to the PC hardware, thereby allowing processes which are otherwise
known as servers to access information from each other using IPC i.e. Inter-Process
Communication. This all topics cover in Linux course training and linux training institutes in
Types of Kernels:
There are different procedures to build an OS kernel and also there are various considerations w.r.t
the architecture when setting up a kernel from its scratch.
Generally kernels can be categorized into three types viz., monolithic, microkernel, and hybrid.
While Linux comes under a monolithic kernel, OS X (XNU) and Windows 7 belong to the hybrid
Brief on the types of Kernels:
A microkernel management approaches coordination between the CPU, memory and IPC while the
other things are considered as an accessory that is to be handled in the user mode. Linux
administration training in Bangalore.
Advantages: Microkernels are portable and eases user’s work on change of video card or operating
system subject to the condition that operating system is still able to access in the same way the PC
hardware. Microkernels have an advantage of a small footprint, in terms of both memory and
installation space, and are secure comparatively owing to its restricted accessibility feature which
does not allow supervision mode dominance.
Disadvantages in Linux course in Bangalore:
Hardware is abstracted more through the drivers
Since drivers are used in user mode therefore hardware may show slow reaction.
Processes can access information in a queue and can’t access other processes immediately.
Monolithic kernels oppositely different from microkernels since besides encompassing the CPU,
memory, and IPC, they also include other things which include device drivers, file management
systems, and system server calls also Linux training institutes in Coimbatore. The pros is that it is
better in terms of hardware access and multitasking domain. This is because when a program needs
any information from the memory or from another ongoing process, it has comparatively better
direct access line and doesn’t have wait for information access. But this is a drawback because more
processes running under supervisor mode leads to more interruptions and process crash.
Better access directly to hardware used for programs
Easier inter communication between processes.
No additional support required for supported devices.
No waiting time for processes.
It has a large install and memory footprint
Less security owing to more processes in supervisor mode.
Hybrid kernels are able to select and choose what they opt for user mode functioning and for
supervisor mode respectively. Certain time things like device drivers and file system I/O in will be
made to function user mode while server calls and IPC might be in the supervisor mode. This kernel
is the best combo of the other two but requires more work on the hardware part because the driver
responsibility completely relies on that. It also has some of the latency problems which
microkernels are prone to.
Flexibility of developer to choose processes assigned to user mode or supervisor mode
Install footprint is smaller than monolithic kernel
Flexibility is more compared to other models
Certain times it faces similar process lag as that of microkernel
User managed device drivers.