EC2 Instance Storage

EBS Volume

• Elastic Block Store Volume :  a network drive that can be attached to running instance
  
  • persist data, even after termiated
    • 데이터를 바이트 블록 단위로 디스크에 저장
  • mounted to one instance at a time(at the CCP level)
  • bount to a specific availability zone
    • 예를 들어, us-east-1a 에서 생성된 경우 us-east-1b에서는 연결 불가능
    • to move a volume across, need to snapshot it
  • uses a network to communicate with an instance, might have latency
  • can be detached from an EC2 instance and attached to another one quickly
  • have to provision capacity in advance
    • size in GBs and IOPS(I/O operations per seconds)
    • can increase the capacity over time 
  • 요금은 '단가 x 저장 시간'
• Delete on Termination 
  • controls the EBS behaviour when an EC2 instances terminates
    • 디폴트 값으로 root EBS volume은 삭제되게 되어 있고, 다른 볼륨들은 X
    • 하지만 수정이 가능함
• EBS Snapshots
  • 특정 타임에 EBS 볼륨의 백업을 만듦
  • 스냅샷을 만들기 위해서 detach 할 필요는 없지만, 권장됨.
  • can copy snapshots across AZ or reigon
  • Features
    • EBS Snapshot Archive
      • move snapshots to "Archive tier" => up to 75% 저렴
      • takes within 24 to 72 hrs to restore the archive
    • Recycle Bin for EBS Snapshots
      • recover snapshots from accidental deletion
      • a day to one year for retention (조정 가능)
    • Fast Snapshot Restore
      • 스냅샷을 완전 초기화, 지연 시간 없앰.
      • 스냅샷이 매우 크고, EBS 볼륨 혹은 EC2 인스턴스를 빠르게 초기화해야 할 때 유용

AMI 

• Amazon Machine Image
• 소프트웨어 구성을 기록한 템플릿
  • 같은 설정의 서버를 빠르게 복제할 수 있음
• customization of an EC2 instance
  • A public AMI 
  • Own AMI
  • An AWS Marketplace AMI
• built for a specific region (can be copied across regions)
• Process
  • start an EC2 instance and customize it
  • stop the instance for data integrity
  • build an AMI (EBS snapshots)
  • launch instances from other AMIs

EC2 Instance Store

• EBS Volumes : limited performance
• Need a high-performance hardware disk, use EC2 Instance Store
• Pros
  • Better I/O performance
  • Good for buffer/cache/scratch data/temporary content
• Cons
  • Lose storage if they're stopped
  • Risk of data loss if hardware fails

EBS Volume Types

• gp2/gp3(SSD)
  • General Purpose SSD volume
  • balances price and performace for a wide variety of workloads
    • cost effective storage, low-latency
  • can be used as boot volumes
  • 1 GiB - 16 TiB
• io1/io2 Block Express (SSD)
  • Highest-performance SSD Volume
  • mission-critical low-latency or high throughput workloads
    • Critical business application with sustained IOPS performance
    • applications that need more than 16,000 IOPS
    • Great for database workloads
  • can be used as boot volumes
  • supports EBS Multi-attach
    • attach one EBS Volume to multiple EC2 instances in the same AZ
    • each instance has full permissons on read &write of the high-performance volume
    • up to 16 EC2 instances at a time
    • must use a file system that's cluster-aware
• st1(HDD)
  • Low cost HDD volume
  • frequently accessed, throughput intensive workloads
  • 125 GiB to 16 Tib
  • Big Data, Data Warehouses, Log Processing
  • Max throughput 500 MiB/s - max IOPS 500
• sc1(HDD)
  • Lowest cost HDD volume
  • less frequently accessed workloads
  • Scenarios where lowest cost is important
  • Max throughput 250 MiB/s - max IOPS 250

EBS Encryption

• Encrypted EBS volume
  • 저장 데이터가 볼륨 내부에서 암호화 됨
  • 인스턴스와 볼륨 간의 전송 데이터 암호화 됨
  • 스냅샷 암호화
  • 스냅샷으로 생성한 볼륨 암호화
• 암호화와 복호화 보이지 않게 처리됨
• 암호화는 지연 시간에 거의 영향 주지 않음
• Process
  • create an EBS snapshot of the volume
  • encrypt the EBS snapshot
  • create new EBS volume from the snapshot
  • attach encrypted volume to the original instance 

 

EFS

• Elastic File System 
  • 관리형 NFS (Network File System)
  • can be mounted on many EC2
  • works with EC2 instances in multi-AZ
  • Highly available, scalable, expensive, pay per use
  • uses NFSv4.1 protocol
  • security group to control access to EFS
  • compatible with Linux Based AMI
    • posix file system, has a standard file API
  • Encryption at rest using KMS
  • File System scales automatically, no capacity planning
• Use Cases
  • content management
  • web serving
  • data sharing
  • Wordpress
• Performance & Storage Classes
  • Scale
    • 1000s of concurrent NFS clients, 10 GB+ throughput
  • Performance Mode(EFS 생성시 설정)
    • General Purpose - latency-sensitive use cases
    • MAX I/O - higher latency, throughput, highly parallel
  • Throughput Mode
    • Bursting - ITB 
    • Provisioned - set throughput regardless of storage size
    • Elastic - automatically scales throughput up or down based on your workloads
  • Storage Classes
    • Storage Tiers
      • standard : frequently accessed files
      • Infrequent Access : cost to retrieve files, lower price to store
    • Availability and durability
      • standard : Multi-AZ, great for prod
      • one zone : One-Az, great for dev, backup enabled by default. over-90% in cost savings
  • EBS vs EFS
    • EFS has a higher price point than EBS
    • Can leverage EFS-IA for cost saving