Unikernels provide a specialized, single-address-space machine image constructed using library operating systems that merges an application and only the necessary parts of an operating system into a single image. This reduces the memory footprint and disk space needed. Unikernels boot directly on hardware without a virtual machine, improving boot speed and reducing CPU usage. They also improve security by having a smaller attack surface and stronger isolation between components compared to traditional virtual machine approaches.

1. Unikernels
Before, now, next
UnikernelsUnikernels
Ayoub El Majjodi
16-07-2020

2. Introduction
First digital computer - 1946
✗
occupied about 1,800 square feet
✗
consisted of :
- 20,00 vacuum tubes
- 10,000 capacitors
- 70,000 resistors
✗
Used 200 kilowatts of electricity
✗
Weighed 30 tons and cost
$487,000

5. ●
VM software layer not well isolate many
application services and users, and there is a
high level of redundancy
●
In order for the app to be debugged and run
well, it should pass through all the essential
libraries till the kernel

6. Unikernels
Unikernels are specialised, single-address-space machine images constructed by using library operating
systems.
●
with Unikernels :
– we don't need all the
applications that are on top of
Kernel, in addition, we don't
even need all the kernel to
make our application run.
– OS + App as one
– Merging application and
what you need from OS in a
single image
– Boot the application directly
on a hardware without VM

7. ●
First, unikernels are small—very small; many come in at less than a
megabyte in size, it literally employs the functions needed to make the
application work, and nothing more
●
Next, unikernels are very quick to start. Because they are so tiny, devoid
of the baggage found in a traditional VM stack
●
Unikernel avoid the hardware compatibility probelms encountred by
traditional library OSs
●
unikernels substantially improve security. The attack surface of a unikernel
machine image is quite small, lacking the utilities that are often exploited
by malicious hackers

8. Summary
●
Cost :
– Reduced memory footprint
– Greatly reduced need for disk space
●
Time :
– Boot speed
– No extraneous process taking up CPU
– Faster load times, lower latencies
●
Security :
– Reduced code size
– Customized to application
– Stronger walls between disparate components