AZ-104 Certification Notes

Chapter 6 - Understanding Storage Accounts

Describing Storage Accounts

• Storage Account
  • Top-level resource for storage purposes inside of Azure
  • Underneath the storage account you have multiple different subservices that provide varying storage options
    • Azure Queue
      • Message-based storage for microservices
    • Azure Files
      • Cloud-based file-sharing service
    • Azure Table
      • Non-relational, semi-structured data storage service
    • Azure Blob
      • Object-oriented storage solution

Components of Storage Accounts

• Account Type
  • Determines features and costs
• Performance Tier
  • Determines performance levels
• Replication
  • Determines infrastructure redundancy
• Access Tier
  • Determines access levels and data costs

Understanding Azure Storage Redundancy

• Region
  • 2-millisecond latency envelopes
  • Inside of these regions we have 1 or more availability zones
    • Inside of each of these availability zones, we have independent power, cooling, and network
    • Each availability zone typically has 1 or more datacenters
• Locally redundant storage (LRS)
  • Storage all 3 copies of data inside the same availability zone
    • If this availability zone were to go down, we would lose this data
• Zone redundant storage (ZRS)
  • Has a copy of our data in each availability zone within a region
    • This can withstand 2 availability zone failures before you lose data
• Geo redundant storage (GRS)
  • Has 3 copies of our data in an availability zone in two different regions
    • 3 copies of data in a single availability zone per region (a total of 2 regions) so 6 copies within 2 availability zones in 2 regions
• Geo-zonal redundant storage (GZRS)
  • This option can provide us the ability to store a single copy of our data in each availability zone in the home region, and then store 3 copies of our data inside of an availability zone in a secondary region
• Read-access geo-zonal redundant storage (RA-GZRS)
  • The same as GZRS, but it's read-access

Key Takeaways

• Account Type
  • General purpose v1
    • Legacy for blobs, files, queues, and tables
  • General purpose v2
    • Recommended for blobs, files, queues, and tables
• Performance Tier
  • Blob storage
    • Legacy blob-specific accounts
  • Standard
    • Default storage performance tier
  • Premium
    • High-performance storage tier
• Replication
  • Locally redundant storage (LRS)
    • Three copies in a physical location within a region
  • Zone-redundant storage (ZRS)
    • Three copies across zones within a region
  • Geo-redundant storage (GRS)
    • LRS in a primary and secondary region
  • Geo-zone-redundant storage (GZRS)
    • ZRS in a primary region and LRS in a secondary region
• Access Tier
  • Hot
    • Frequently accessed data
  • Cold
    • Infrequently accessed data
  • Archive
    • Backup data rarely accessed