AWS Certified SysOps Administrator Part V: EBS

 

  • 1. EBS
    • a. Storage Types
      • i. Instance Store
        • 1. Ephemeral
      • ii. S3
        • 1. Standard
        • 2. RRS
      • iii. EBS
        • 1. GP-SSD
        • 2. PIOPS
        • 3. Magnetic
      • iv. EFS
        • 1. Network Attached Storage
        • 2. Managed file system
        • 3. Only supports Linux instances
    • b. EBS Characteristics
      • i. Billed on storage capacity and I/O
      • ii. Does not need to be attached to an instance
        • 1. Detach and re-attach
      • iii. Transferred between availability zones
      • iv. EBS volumes are designed for an annual failure rate (AFR) of 0.1 – 0.2 %
      • v. The average failure rate for a hard drive is 5-10%
      • vi. EBS volume data is replicated across multiple servers in an availability zone
      • vii. SLA: 99.95%
    • c. EBS Volume Types
      • i. General Purpose (SSD)
        • 1. Use cases
          • a. System boot volumes
          • b. Virtual desktops
          • c. Small to medium DBs
          • d. Dev and test
        • 2. Volume Size: 1GB – 16TB
      • ii. Provisioned IOPS (SSD)
        • 1. Use cases
          • a. I/O intensive
          • b. Relational databases
          • c. NoSQL databases
        • 2. Volume Size: 4GB – 16TB
      • iii. Magnetic
        • 1. Use cases
          • a. Infrequent data access (archiving)
          • b. SSD has come down in price
        • 2. Volume size: 1GB – 1TB
      • iv. Features
        • 1. Bursting will usually happen when an instance starts to increase boot time
        • 2. 48,000 max IOPS
        • 3. 800 Mbps max throughput
    • d. Increasing IOPS performance
      • i. Stripping multiple volumes into a RAID-0 group
        • 1. Cheaper alternative to provisioned IOPS
        • 2. This works because each disk has its own max IOPS
        • 3. When you use RAID-0 your max IOPS is the summation of the max for all your disks
        • 4. With RAID-0 you do risk losing a drive if one drive fails
        • 5. RAID-5 or RAID-6 might be more reliable
        • 6. Function of the guest OS
        • 7. EBS is not designed for long term storage, S3 targets that use case
      • ii. EBS-Optimized instances
        • 1. Dedicated capacity for Amazon EBS I/O
        • 2. 500 – 4000 Mbps performance boost
        • 3. Supported instance families:
          • a. C, D, M, R, G
          • b. Varies from type to type, need to look up in AWS documentation to confirm
        • 4. GP-SSD within 10% of baseline and burst performance 99.9% of the time
        • 5. PIOPS within 10% of provisioned performance 99.9% of the time
        • 6. EBS optimized are designed for all EBS volume type
        • 7. Additional hourly fee
  • 2. Snapshots
    • a. Characteristics
      • i. Point-in-time snapshots
        • 1. Taking a snapshot of a running instance: Nothing going on will be taken into account, not a clean cut over.
        • 2. Power down and then cut over.
      • ii. Support incremental snapshots
        • 1. Only the changes between the last snapshot (saves a lot of space)
        • 2. Billed only for the changed blocks
      • iii. Deleting a snapshot removes only the data not needed by any other snapshot
      • iv. Should I delete this one first or not
        • 1. AWS keeps track of enough information about the snapshot to know which snapshots are dependent on others
      • v. EBS leverages S3 for snapshot storage
        • 1. Not necessisarily inside a bucket…its storage in a special location and accessible from you instances through the management portal
    • b. Features
      • i. Resizing EBS volumes
      • ii. Sharing EBS snapshots
      • iii. Copying EBS snapshots across regions
      • iv. Lazy loading
        • 1. Very slow due to being stored on S3
        • 2. Pre-warming of EBS volumes
          • a. Process changes on Windows and Linux
            • i. “dd for windows” will read all blocks at the same time (accelerate a recall process from S3)
      • v. Create AMI images from snapshots so you can launch instances from it

One thought on “AWS Certified SysOps Administrator Part V: EBS

  1. Pingback: AWS Certified SysOps Administrator Exam: Study Guide | Sky Cliffs

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