AWS认证准备-a Cloud Guru笔记 2, EC2 and EBS

EC2 101

EC2 Options

  • on demand (by seconds/hours), fixed rates
  • reserved, 1 or 3 years term
  • spot, users can bid whatever price you want for instance capacity
  • dedicated hosts (able to use existing server bond software license to save money)

On Demand

  • application with short term, spiky or unpredicable workloads
  • app tested on EC2
  • perfect for users who want low-cost and flexibility without any up-front payment or unpredictable workloads

Reserverd Instances (RI)

  • apps with steady states or predictable usafe (like web server)
  • appws required reserved capacity
  • standard up to 75% discount
  • convertible up to 54% discount
  • schedules RIs (every friday, every December)

    spot instances

  • apps with flexile start and end times
  • apps that are only feasible可行 at very low compute prices
  • users with urgent need for large amount of additional computing capacity
if it is terminated by AWS, you will not charged by partial hours, but if you do, the whole hours will be charged

Dedicated Hosts

  • for regularoty requirements that may not support multi-tenant virtualization
  • licensing which does not support multi-tenancy or cloud deployment
  • can be purchased on demand or reserved (up to 70%)


not require memorary

Screen Shot 2018-12-02 at 7.47.57 AM.jpg

AWS make fake one for exam. you can memrary in
Fight Dr Mc PX
Screen Shot 2018-12-02 at 7.53.11 AM.jpg


  • in a spercific AZ
  • storage volumes attached to your EC2, when attached, you can create file system on it, run a db or as a block

EBS Types


  • GP2 /General Purpose SSD
    • balance price and performance
    • ratios of 3 IOPS per GB with up to 10,000 IOPS and the ability to boost 3000 IOPS for extended periods of time for volumes at 3334 Gib and above
  • IO1 / Provisioned IOPS SSD
    • for I/O intensive apps, large relational db/NoSQL db
    • use it if you need more than 10,000 IOPS


  • ST1 / Throughput Optimized HDD
    • big data
    • data warehouse
    • log processing
    • cannot be a boot volumen
  • SC1 Cold HDD
    • lowest cost for IA workload
    • file server
    • cannot be a boot volumen
  • Standard / Magnetic

  • lowest cost per gb of all EBS which is bootable
  • ideal for workloads that data is IA and apps want low cost

EC2 Instance

  • one subnet one AZ
  • default monitoring is every 5 minutes, 1 minute cloudwatch detailed is charged
  • security group is a firewall A security group is a set of firewall rules that control the traffic for your instance.
  • default user is ec2-user

Security Group

  • any update of security group, it work immediately
  • security groups is stateful, when you add an inbound rule, out bound rule will work too (vpc network rules are not, they are stateless, add one inbound, u have to add one outbound too)
  • you cannot block IP, not like vpc network ACL
  • All port default is block, add it as a rule to allow, all outbound is allowed defaultly
  • an instance can have many security groups, a group can have many too
  • you cannot deny rules

EBS Elastic Block Store

  • standard we cannot modify volume
  • ec2 instance and EBS volume are in the same AZ
  • Use snapshot to transfer to another AZ
  • create snapshot -> copy to another region to move by region