Summary Controlling and Managing Systems

 Kernels
o Kernels are computer programs that are at the centre of the operating system and
allows complete control over the system.
o They can:
 Manage the device
 Memory
 Computers resources
 Security
 Allocate memory to applications so they can operate
o They work by:
 It starts up (first thing the device does at start up)
 The kernel remains in the computer memory to help support the running of
the device
 Kernel is small as it stays in the memory but doesn’t interfere with smooth
running of the machine
 Loaded to protect area to stop being deleted or overwritten
 Every operating system has kernels
 Different operating systems have different type of kernels
 Monolithic kernels
o Linux is an example of an older monolithic kernel
o Problems
 Poor maintainability
 Bug fixing required
 The size of the kernel was huge
 This slows the device down
o New systems
 Kernels are packaged in multi-modules which can be loaded/unloaded
separately as they perform different operations on the machine
o Maintenance benefits
 Maintenance can be done on each separate kernel without restarting the
whole system
 Micro Kernel
o