SU05: System Management, Mobile OS

Question 1

System Monitoring

What does system monitor and what does it know

Answer 1

Process: if some processes are taking up too much space
Memory: system memory is enough
Disk usage: know whether partitions are filled up, any unusually large foler size.
Log files: check for error/unusual activity

Question 2

Quota VS reservation

Answer 2

quota: maximum space
reservation: minimum space

Question 3

Quota is to ensure

Answer 3

OS partition doesn’t run out of space

Question 4

Mobile OS vs Desktop OS

Answer 4

single user vs multiuser
not critical to add devices into machine
ability to extend battery power
less vs more memory/storage space
less mulitasking (conserve battery life, system resource) vs more multitasking

Question 5

iOS layers

Answer 5

Cocoa Touch (application layer, frameworks dealing with development, provide API)
media Layer (frameworks dealing with media)
Core Services (frameworks: address book, core location)
Core OS (low level features - security framework)

Question 6

iOS characteristics

Answer 6

use Grand Central Dispatch - multi-core support capability
Convienient for developers to spilt program to multiple threads
develop more efficient programs
Hard to make
More secure
enhance parallelism - phone running smoothly with multiple applications

Question 7

Android OS Layers

Answer 7

applications [Java]
application framework (App managers) [Java]
system libraries (System Functions) , android runtime (Core Libraries, Virtual Machine) [C, C++]
**Linux Kernel **(Drivers, power management) [C]

Question 8

Android runtime Characteristics

Answer 8

not directly compiled on hardware
mapped into bytecode format
transformed into native instructions on device

Question 9

Application Framework Characerstics

Answer 9

High level building blocks used - reusability of components
Application Programming Interface - enhanced standardisation