VL 4

Question 1

AWS - Resource Distribution

Answer 1

Scalability, fault tolerance in availability because of many regions

Question 2

AWS - Availability Zones

Answer 2

Two zones have no common points of failure => servers in two zones gain infrastructural redundancy
Communication in one zone is free, between zones not

Question 3

AWS - SLA

Answer 3

Service Level Agreement
Region level: region is unavailable, when all of your running instances or tasks, deployed in two or more AZs, concurrently have no external connectivity
Instance- level: instance is not available, when your Single EC2 instance has no external connectivity

Question 4

Xen Hypervisor

Answer 4

3 levels of virtualization: bare metal, hosted, os level
Xen: bare metal Hypervisor

Question 5

Nitro Hypervisor

Answer 5

Services are now part of the hardware

Question 6

Amazon Machine Image (AMI)

Answer 6

Copy of server with OS and pre installed software
AMIs are stored in S3

Question 7

AWS Storages

Answer 7

Amazon Elastic block storage: physical disks accessible to the network
Amazon EC2 Instance Storage: physical disks connected to the server on which VM will be placed
Amazon Elastic File System: Network attached system
Amazon simple storage service: place blob of data

Question 8

RAID

Answer 8

Increase bandwidth, fault tolerance
(Create copies)

Question 9

Local storages

Answer 9

RAID
FLASH: non-volatile memory
Single and Multi level Cells

Question 10

Data center storage

Answer 10

Only flash or SSD

Question 11

Provisioning of storage

Answer 11

Direct attached storage
Storage area network: independent from LAN
Network Attached Storage

Question 12

SAN pros

Answer 12

Flexible distribution of devices between clients
Easy replacement of faulty servers with new servers booting the same unit
Easier disaster protection

Question 13

SAN cons

Answer 13

Shared network bandwidth
Shared performance of storage devices
Security concerns due to transfer data through network

Question 14

Network attached storage (NAS)

Answer 14

File server attached to the network
Frequently using internally a RAID to get redundancy

Question 15

Storage virtualization

Answer 15

Block virtualization or file virtualization
Usage:
Flexible mapping, thin provisioning, disk expansion and shrinking, non-disruptive data migration, improved utilization

Question 16

Block virtualization: Implementation

Answer 16

Host based: host runs virtualization software
Storage device based: disk array provides virtualization level
Network based: virtualization device is in the LAN and connected to SAN

Question 17

File virtualization

Answer 17

Where file is to find
File systems
Clustered NAS
Distributed File System

Question 18

Amazon Block Storage

Answer 18

Block level storage which can be mounted
Can be formatted as appropriate
Multiple can be combined into a virtual RAID
Snapshots of block storage volume are stored in S3 for backup or replication

Question 19

Amazon Instance Storage

Answer 19

Disk attached to the physical host
If stop or terminate instance, all data lost

Question 20

Amazon Elastic File System

Answer 20

Scalable file storage
Can be created and mounted into instances
Files can be shared among instances
File system has to be explicitly created and destroyed

Question 21

Amazon Simple Storage Services (s3)

Answer 21

Reliable and inexpressible data storage infrastructure
Two level namespace:
buckets
Objects: file in buckets
High durability but low availability

Question 22

Amazon EC2 Instance

Answer 22

Running VM which is based on an AMI
Elastic IP Adress

Question 23

Security Platforms

Answer 23

EC2 classic, EC2-VPC (Virtual Private Cloud)

Question 24

EC2 access

Answer 24

Through a web services API

Question 25

AWS Cloud Formation

Answer 25

Model infrastructure